I just registered today with Commission junction and having a lot of questions about it.

How actually to earn with it ?
Which method should I use to earn from it ?
Is it really worth it ?



As I am a newbie to CJ, a step by step guide would be great.

You basically sell products and/or leads. The types of products depends on what your website is about. It's quite hard to make a lot of money with CJ if you don't get many visitors, if you don't have a large audience. Some people juggle pay per click campaigns against the price of the products they're seeling through CJ - this can take a lot of experimenting to get anywhere with it though.