Affiliate AgenciesThese are agencies which serve as a connection between an affiliate marketer and the company that the affiliate marketer is promoting. You can register with one of these companies and then get special links to certain products. Put these links on your blog or website, and when someone clicks that link and then buys a product, you get a commission.
My personal favorite: Shopzilla (you can see more data at this post).
One Network Direct
Join LinkConnector.com Network
For a list of good affiliate programs to join:
A list of "Top 50" Affiliate Agencies:
For more ideas, see Holly's Ebook (here).
I also should mention that I can no longer recommend Clickbank at all - ESPECIALLY for new affiliate marketers. To understand, read their rules.
The gist is, you don't get a commission unless you have at least 5 purchases, some from VISA, some from Mastercard. And if your account goes too long without income, the balance starts to decrease every payment period. For exact specifics, see the site and their rules.