I suggest watching a lot of videos and hiring a coach if at all possible. The form is very complex, and reading an explanation probably isn't going to cut it if your form needs work.
Flip through P-funk's thread called Amazing Olympic Lifts (Or something like that). There are a lot of awesome links to people doing the C&J and snatch.
Also, don't be afraid to practice with some light weights. When I come back I will definitely be sticking to really light weights for a while. I can probably power clean about 225, but I'm just going to be doing sets of 135 (8 sets x 3 reps), just to give you an idea of how light I'm talking.