Well their main website "CrossFit: Forging Elite Fitness" is an okay place to start - along with their 'What is Crossfit?' and their library of Crossfit Exercises - I don't LOVE their website setup, but there is a lot of information there.
Probably the BEST place is to see if a local affiliate (crossfit gym) has a website, they usually explain how THEY work, what their schedule is, their philosophy on workouts, etc. You can find a local affiliate on their Official CrossFit Affiliate Gym Locator
I'm really lucky that my company pays one of the owners of a local Crossfit Affiliate to come into our gym and have classes almost every day. I think that's too much for my goals, so I usually just go Fridays to shock my system with a crazy workout. Crossfit memberships are expensive so without that I don't think I would do it.
HOWEVER, once you are familiar with the workouts and proper mechanics - there are a LOT of things you can do on your own equipment, in local parts, wherever. Then there are things like The WOD Shop - Online CrossFit Workout of the Day (WOD) Generator that can help you put together your workout.
Uh... hopefully I put something useful in there somewhere