Full details here:
http://www.wowwiki.com/Formulas:Honor_System
It's complex, but I will attempt a simple explanation...
Each week (Tuesday maint.) weekly honor is summarized. The person with the highest honor total gets #1 standing for the week and 13,000 ranking points. everyone underneath him gets a proportionately lower number of ranking points. According to wowwiki, the finction is a straight line between certain standing numbers, as demonstrated on this graph at the wowwiki link:
http://www.wowwiki.com/Image:RPvsCP-examp.png
Supposedly, the change in the 1.12 patch change the 'breakpoints' for these standing numbers so if people were clustered near #1, or any 'breakpoint' those just below would get higher overall ranking points.
PvP rank is a cumulation of your ranking points... minus decay. Every week you lose 20% of your total if you have more than 25 HKs (only 10% if you have fewer than 25 HKs).
So you can figure how many ranking points you got this week by using the following formula:
This weeks ranking point total - (Last Weeks ranking point total * 0.8) = ranking points gained this week
Aside from rank 1 and 2, ranks are every 5000 ranking points.
Rank1 = get X HKs ( I think X = 25, some incredibly low number)
Rank2 = 2000 ranking points
Rank3 = 5000 ranking points
Rank4 = 10000 ranking points
etc....
You can figure your approximate maximum rank given infinite time by multiplying your weekly ranking point total by 5. In reality it will be slightly lower than this, because things move very slowly once you approach the theoretical maximum.
That being said, it's supposedly only about 2-5 weeks until the patch that will completely remove this whole system and will substitute an alternate system for getting rewards from PvPing, so set your goals accordingly.
Conc / Concillian -- Vintage player of many games. Deadly leader of the All Pally Team (or was it Death leader?)
Terenas WoW player... while we waited for Diablo III.
And it came... and it went... and I played Hearthstone longer than Diablo III.