check out crossfit.com it will tell you everything you want to know about crossfit.
I've been part of crossfit since 06. The hardest part is finding a good balace with crossfit. For years I went 5-6 days a week and often felt like I got run over by a truck.
I finally found 3 days a week doing a wod and a tabata wod once a week.
It works for sure.
I got a level 1 cert. in 08 and the running and endurance cert.
I teach a crossfit styled bootcamp 2 days a week. It will get you in shape that's for sure ;-)
Dirt Diva