Ok, here we go, this seems to be a good place to start….
So what is affiliate marketing?
The definition of affiliate marketing:-
It’s the sharing of revenue between merchants and salespeople, where an agreed commission is paid for a sale of a product or service or even just a lead.
Let’s say you are interested in golf, and decide you want to sell golf clubs online, you find a website that not only sells golf clubs (obviously) but also has an affiliate program, you just give them a few details, who to write cheques to etc, and that’s it, you are given a special link to promote that tracks your customers and gives you the credit for each sale, easy huh?
You are paid for performance, if you don’t sell anything you don’t get paid, it’s entirely upto you how (within reason, no spamming for instance!), when, and how often, don’t worry they won’t be ringing you aking why you haven’t sold anything, you aren’t contracted to them.
Some companies have their own inhouse programs, others do it through a third party of which the most popular ones are:-
cj.com From physical products to pay per lead (You will find your golf club merchants here)
clickbank.com Digital products only (This is where you buy all those crappy ebooks 
)
paydot.com Physical and digital Products