I'd highly recommend checking out
http://www.adult-webcam-faq.com - it's run by a former cam girl and has reviews of just about every webcam site out there, including what are good ones to work at (see Exhibitionists Pros/Cons and comments in each review)
She also has a forum there with one devoted to working girls. There are a few there who have a lot of experience and you'll pick up a lot of tips just reading past posts.
Hope this helps and good luck!
