Let me be blunt: go for the biggest damn case you can get. The bigger, the better. Why? Easy.
1) Room for expansion. New video cards take up more and more space. Likewise for sound cards. The more space you got, the more you can throw in there. Think of it like buying a mini-van when you're a newly-wed with a baby in the oven, rather than waiting till you've got two kids and are still putzing around in that 2-door.
2) Cooling. More open space leaves not only more room for more, better fans, but also for alternative cooling sources (like water cooling). Not only that, but if there's not enough space, the air can't flow, and you'll cook your whole box. Not a pretty site. This goes DOUBLY so for AMDs, as they overheat like you wouldn't believe. It'd take longer to cook one on a stove than by simply removing the heatsink. Not so with a P4.
3) When it comes time to fix something, change something, etc., the bigger case will give you MUCH more room to work in. Small cases are a PITA to work with when it comes to maintenance / repair, and upgrades. You do NOT want to be stuck with a small case when stuff starts crapping out on you.
4) The only reasons you could POSSIBLY want a small form factor case for are a) portability (buy a laptop), or B) style. Gaming machines are NOT "stylish" by nature, and you can buy some of the most exotic large cases around. No small form factor case is gonna allow you to throw in a temperature guage, neon tubing, and plexi-glass windows, now are they? :P
Bottom line: Don't get an SFF, unless you can justify it. DO get the biggest case you can. DON'T get a mid-size chassis. DO get a full-size chassis. You'll thank me.
And one more thing on chassis:
Aluminum is costly, but it's LIGHT. If you can afford it, I HIGHLY recommend getting an aluminum case. Not only are they stylish and popular, but when it comes to moving them around, you'll REALLY notice the difference in weight, especially when it's fully loaded. Take it from a PC tech who moves his boxes around (and changes hardware configurations) several times daily. The weight can be brutal, especially if you're stuffing it in tight quarters.
Edit (Additions):
Monitors - 19" - 21" if you can afford it and fit it, 17" if you can't. Anything less, and you'll be straining your eyes. I know. ;) ALWAYS go with a flat-screen CRT. NEVER go with a flat panel unless you really want the space savings. Flat panel LCDs have graphical distortion similar to that seen on laptops. As such, they make horrible monitors for gaming. Fast movements leave "trailing", meaning the images can sorta blur. Big no-no for fast-paced, high action games (ala BF1942). Personally, I love NEC. They're cheap, and they're GOOD. I've heard that ViewSonics are also very good, but I wouldn't know. Whatever you do, stay away from eMachines and Proview, and typically also Sony (IMHO). eMachines and Proview are just horrible.
http://www.nec.com/
http://www.viewsonic.com/
Power Supplies - Enermax are good. Just stay away from anything that sounds cheap. A cheap power supply will crap out on you within the first 6 months, guaranteed. And you don't need that kind of hassle.
Cases - Thermaltake has some very stylish cases. Cooler Master / Enermax have your basic case, and your more styled case. Lian-Li cases are some of the best on the market. HIGHLY recommended.
http://www.maxpoint.com/pccases.htm
http://www.coolermaster.com/case/
http://www.thermaltake.com/products/caseMenu.htm
http://www.thermaltake.com/products/Xaser3Menu.htm
http://www.lian-li.com/
Cooling - If you can afford it, and you feel up to the challenge, go with water cooling. Expensive, and alot of assembly, but WELL worth it. Exceptional cooling power, and any PC tech's wet dream. ;) If you go with fans, I recommend Thermaltake. Again, stay away from anything cheap. A cheap fan will die fast, and take alot of stuff with you. Proper cooling is ESSENTIAL to any PC, as over-heating can cook your CPU, your vid card, and your board very quickly. A $5 fan could cost you $500 in damages, so don't be stingy. But, you don't have to go with a $40 fan, either. Use your head, and you'll be fine. Good brands are Thermaltake and Cooler Master.
CD/DVD-ROM - Cheap drives aren't worth the savings. Get something decent. Mitsumi, Samsung, Pioneer, etc. are all good brands. Just don't get anything "Generic" or cheap, and you'll be fine.
Floppy - What's to say? Get what there is. Mitsumi is fine. They're so cheap, and hardly anyone makes them, so don't expect to spend alot of time on this one.
Keyboard / Mouse - Rule #1: NOTHING WIRELESS. There's nothing worse than having your mouse die in the middle of a game, and they eat batteries. Rule #2: OPTICAL MOUSE. Anything less, and I'll strangle you with your mouse cord. Rule #3: Expensive keyboards are usually a waste, unless they boast some features that you want (style, comfort, etc.). For the most part, a $5 keyboard is gonna be just as good as a $30 one. All personal preference.
Video Cards - If you're going nVIDIA, I'd recommend PNY, Chaintek, MSI, or Gainward. PNY / MSI are very good, but Chaintek and Gainward aren't bad. Other than that, I'd steer clear, and READ THE REVIEWS. I cannot stress this enough. A single card type can vary WIDELY in performance depending on who makes it (NOT the chip, but the card itself!). Research, research, research, or you'll be sorry.
Operating System - Windows 98, possibly dual-booting with Windows 2000. If you've never used Windows before, TRY Windows XP before you get sucked into buying it. Alot of places, particularly computer building sites, only sell XP. Also, if you get XP, do NOT get Home Edition, at all costs. Get Professional, or get nothing. It's as simple as that. And, READ UP on OSes. XP has alot of features, and may be better for gaming than 2000 (I run 2000 with almost no problems, save for legacy games that only run on 95 / DOS, and there are ways around that; I also have Windows 98, so I can run them if I want; it's just not installed), but it has ALOT of annoyances, too. Some small, some absolutely monstrous. Try it before you buy it, and get other people's opinions. My vote goes for Windows 98 for gaming, Windows 2000 for general usage, and Windows XP as a last resort. If you really want, get 98 and 2000, and dual boot. 98 is good for gaming, but stability isn't great. Windows 2000 is VERY stable, but lacks the backwards-compatability for gaming that Windows 98 has. Your choice.
General tips - Watch the prices. See what goes up, what goes down. See WHY it does that (i.e. new hardware comes out, simple passing of time, etc.). Compare the different items and costs. Compare bang / buck, and always research the PRODUCT and the VENDOR. Always, always, always.
Good luck with your hunting. It's good that you're setting time aside to do this. If you need any help whatsoever, feel free to ask me. I graduated from Clark University's PC Service & Support class, as well as their Windows 2000 Microsoft Certified Professional class (basically, I'm an uncertified A+/Net+/MCSE who's working on getting his certs), so I know a fair bit about computers. And, I've been taking computers apart and rebuilding them for several years, often multiple times in a single day. I can strip and rebuild a PC from completely in about an hour, and I know the ins and outs of all the hardware, so I can give you pointers on how to put it all together. Also, on occasion I do research into building PCs as a hobby, planning out the products, compiling price lists, etc. Just to stay on top of things, and because I love the industry. If you need any pointers in that area, feel free to ask.
Building a PC is easy, provided you know how. It CAN look daunting, but PCs today are DESIGNED to be easy to put together, unlike years ago. Most hardware has PLENTY of instructions, and more people are knowledgeable about how to build / maintain them now than ever before. Ask your friends, ask your family, ask your coworkers. No matter what, SOMEONE will have the answer.
1) Room for expansion. New video cards take up more and more space. Likewise for sound cards. The more space you got, the more you can throw in there. Think of it like buying a mini-van when you're a newly-wed with a baby in the oven, rather than waiting till you've got two kids and are still putzing around in that 2-door.
2) Cooling. More open space leaves not only more room for more, better fans, but also for alternative cooling sources (like water cooling). Not only that, but if there's not enough space, the air can't flow, and you'll cook your whole box. Not a pretty site. This goes DOUBLY so for AMDs, as they overheat like you wouldn't believe. It'd take longer to cook one on a stove than by simply removing the heatsink. Not so with a P4.
3) When it comes time to fix something, change something, etc., the bigger case will give you MUCH more room to work in. Small cases are a PITA to work with when it comes to maintenance / repair, and upgrades. You do NOT want to be stuck with a small case when stuff starts crapping out on you.
4) The only reasons you could POSSIBLY want a small form factor case for are a) portability (buy a laptop), or B) style. Gaming machines are NOT "stylish" by nature, and you can buy some of the most exotic large cases around. No small form factor case is gonna allow you to throw in a temperature guage, neon tubing, and plexi-glass windows, now are they? :P
Bottom line: Don't get an SFF, unless you can justify it. DO get the biggest case you can. DON'T get a mid-size chassis. DO get a full-size chassis. You'll thank me.
And one more thing on chassis:
Aluminum is costly, but it's LIGHT. If you can afford it, I HIGHLY recommend getting an aluminum case. Not only are they stylish and popular, but when it comes to moving them around, you'll REALLY notice the difference in weight, especially when it's fully loaded. Take it from a PC tech who moves his boxes around (and changes hardware configurations) several times daily. The weight can be brutal, especially if you're stuffing it in tight quarters.
Edit (Additions):
Monitors - 19" - 21" if you can afford it and fit it, 17" if you can't. Anything less, and you'll be straining your eyes. I know. ;) ALWAYS go with a flat-screen CRT. NEVER go with a flat panel unless you really want the space savings. Flat panel LCDs have graphical distortion similar to that seen on laptops. As such, they make horrible monitors for gaming. Fast movements leave "trailing", meaning the images can sorta blur. Big no-no for fast-paced, high action games (ala BF1942). Personally, I love NEC. They're cheap, and they're GOOD. I've heard that ViewSonics are also very good, but I wouldn't know. Whatever you do, stay away from eMachines and Proview, and typically also Sony (IMHO). eMachines and Proview are just horrible.
http://www.nec.com/
http://www.viewsonic.com/
Power Supplies - Enermax are good. Just stay away from anything that sounds cheap. A cheap power supply will crap out on you within the first 6 months, guaranteed. And you don't need that kind of hassle.
Cases - Thermaltake has some very stylish cases. Cooler Master / Enermax have your basic case, and your more styled case. Lian-Li cases are some of the best on the market. HIGHLY recommended.
http://www.maxpoint.com/pccases.htm
http://www.coolermaster.com/case/
http://www.thermaltake.com/products/caseMenu.htm
http://www.thermaltake.com/products/Xaser3Menu.htm
http://www.lian-li.com/
Cooling - If you can afford it, and you feel up to the challenge, go with water cooling. Expensive, and alot of assembly, but WELL worth it. Exceptional cooling power, and any PC tech's wet dream. ;) If you go with fans, I recommend Thermaltake. Again, stay away from anything cheap. A cheap fan will die fast, and take alot of stuff with you. Proper cooling is ESSENTIAL to any PC, as over-heating can cook your CPU, your vid card, and your board very quickly. A $5 fan could cost you $500 in damages, so don't be stingy. But, you don't have to go with a $40 fan, either. Use your head, and you'll be fine. Good brands are Thermaltake and Cooler Master.
CD/DVD-ROM - Cheap drives aren't worth the savings. Get something decent. Mitsumi, Samsung, Pioneer, etc. are all good brands. Just don't get anything "Generic" or cheap, and you'll be fine.
Floppy - What's to say? Get what there is. Mitsumi is fine. They're so cheap, and hardly anyone makes them, so don't expect to spend alot of time on this one.
Keyboard / Mouse - Rule #1: NOTHING WIRELESS. There's nothing worse than having your mouse die in the middle of a game, and they eat batteries. Rule #2: OPTICAL MOUSE. Anything less, and I'll strangle you with your mouse cord. Rule #3: Expensive keyboards are usually a waste, unless they boast some features that you want (style, comfort, etc.). For the most part, a $5 keyboard is gonna be just as good as a $30 one. All personal preference.
Video Cards - If you're going nVIDIA, I'd recommend PNY, Chaintek, MSI, or Gainward. PNY / MSI are very good, but Chaintek and Gainward aren't bad. Other than that, I'd steer clear, and READ THE REVIEWS. I cannot stress this enough. A single card type can vary WIDELY in performance depending on who makes it (NOT the chip, but the card itself!). Research, research, research, or you'll be sorry.
Operating System - Windows 98, possibly dual-booting with Windows 2000. If you've never used Windows before, TRY Windows XP before you get sucked into buying it. Alot of places, particularly computer building sites, only sell XP. Also, if you get XP, do NOT get Home Edition, at all costs. Get Professional, or get nothing. It's as simple as that. And, READ UP on OSes. XP has alot of features, and may be better for gaming than 2000 (I run 2000 with almost no problems, save for legacy games that only run on 95 / DOS, and there are ways around that; I also have Windows 98, so I can run them if I want; it's just not installed), but it has ALOT of annoyances, too. Some small, some absolutely monstrous. Try it before you buy it, and get other people's opinions. My vote goes for Windows 98 for gaming, Windows 2000 for general usage, and Windows XP as a last resort. If you really want, get 98 and 2000, and dual boot. 98 is good for gaming, but stability isn't great. Windows 2000 is VERY stable, but lacks the backwards-compatability for gaming that Windows 98 has. Your choice.
General tips - Watch the prices. See what goes up, what goes down. See WHY it does that (i.e. new hardware comes out, simple passing of time, etc.). Compare the different items and costs. Compare bang / buck, and always research the PRODUCT and the VENDOR. Always, always, always.
Good luck with your hunting. It's good that you're setting time aside to do this. If you need any help whatsoever, feel free to ask me. I graduated from Clark University's PC Service & Support class, as well as their Windows 2000 Microsoft Certified Professional class (basically, I'm an uncertified A+/Net+/MCSE who's working on getting his certs), so I know a fair bit about computers. And, I've been taking computers apart and rebuilding them for several years, often multiple times in a single day. I can strip and rebuild a PC from completely in about an hour, and I know the ins and outs of all the hardware, so I can give you pointers on how to put it all together. Also, on occasion I do research into building PCs as a hobby, planning out the products, compiling price lists, etc. Just to stay on top of things, and because I love the industry. If you need any pointers in that area, feel free to ask.
Building a PC is easy, provided you know how. It CAN look daunting, but PCs today are DESIGNED to be easy to put together, unlike years ago. Most hardware has PLENTY of instructions, and more people are knowledgeable about how to build / maintain them now than ever before. Ask your friends, ask your family, ask your coworkers. No matter what, SOMEONE will have the answer.
Roland *The Gunslinger*