http://www.tomshardware.com/reviews/anti-aliasing-nvidia-geforce-amd-radeon,2868.html
Wasn't sure if this should be put under performance, or video, or general discussions ... move as you see fit.
This is an excellent article by Tom's Hardware (a pretty good general site with lots of other info, too) that will provide a base understanding and some tips on tuning your card. I was aware of a lot of these items, but there were a few new ones ... plus it's a nice refresher.