Help my computer not suck

[Walkiry]

I heard about the nVidia nForce 2 chipset, but don't know what precisely makes it so good, or what i would need to take advantage of it's special features (whatever they are).  Also, are there any affordable mainboards made with this chipset or is this an "enthusiast" item?

There are several things that make this a good board. Good support for pehripherals (if you've had a not so good board and use USB components you'll know what I'm talking about), a wide range of configuration options, dual DDR support (to increase memory bandwidth), excellent integrated controllers (IDE, Serial ATA, Ethernet, you name it). The overall stability of the board is the best selling point.

You can go for a board with all the fruit (will set you back 125-150 bucks) or simpler versions that don't have as many integrated peripherals like the Asus A7N8X-X for example. It'll be slightly more expensive than an equivalent board with a VIA chipset, but the difference is small and well worth it. You'll hardly need anything too special for using this chipset (it's sometimes recommended that you get twin memory chip pairs for the dual DDR channel, but unless you're one of those enthusiasts you were referring to, it'll hardly be worth it).

Also:

Though it's often recommended, I haven't noticed any improvements in games from having the pagefile on a different physical drive.

That could also be because of how you have your drives partitioned. I have two 120 7200 rpm drives, the OS partitions are the very first of one of the drives (so that they're closer to the outside of the physical platter) and the swap file is also in the very first partition of the other drive, and there's some performance increase (not much, but worth it too).