Signing up through an Affiliate Network is a great way to get started as an affiliate marketer. You can earn extra cash doing it. Best of all it's free. However many times the links to signing up are hard to find (even on merchant web sites they're usually at the bottom of the front page).
I thought this bears repeating.
Here's get into how to sign up as an affiliate on Link Share, Commission Junction, and Clickbank. You usually just need to have a web site (I've used this blog). Some companies require minimum traffic or a dedicated site.
When you sign up with a CPA network and join a merchant's program you'll get a unique URL to the product. They will provide ads, banners, and other creative to help you promote their products. You'll also learn the commission amount they offer.
Clickbank – https://login.clickbank.net/signup/?&reseller=surveys2
The place to buy ebooks or promote them. After your application is accepted, search for an ebook. Click on the 50% link (or whatever percent they pay out). This launches a popup browser with a box to enter your affiliate username. Insert the ID you got when you signed up. You'll get a unique URL.
When you log in you'll get your stats. It's hard to figure out how to get from there to the marketplace. Follow this link to buy or browse ebooks on Clickbank. It's also a good place to sell your content. Since Clickbank manages all merchants on their servers, you can trust you'll get credited for every sale you send them.
Ebooks have great profit margins. The information in ebooks is often cutting edge and highly relevant. Reading ebooks is one of my favorite ways to learn about internet marketing. There are links in ebooks that lead you to additional resources online.
Commission Junction application – https://signup.cj.com/member/publisherSignUp.do
Commission Junction calls affiliates publishers. After you're accepted, log in on the home page by clicking "CJ Account Manager". It drops down with a login. I learned this from the Commission Junction booth at an AdTech or it would've taken me much longer to figure out.
Once you're in it takes some time to learn how to get links. Commission Junction has videos to teach new publishers how the site works.
Commission Junction has email. Most people don't know merchants can only reach you through this email system. You can find out how to contact merchants through the merchant page. Otherwise everyone's identity is confidential.
Link Share – Pretty straightforward. The interface is a bit clunky (to get links, see your programs, etc) once you're in though. There's a login on the top right side of the home page that says "client login".
Hope this helps. Last, I must plug Jeremy Palmer's ebook. Even if you're an internet marketer (beginner through advanced intermediate) you'll learn from this ebook. High Performance Affiliate Marketing is 100% guaranteed. There is no risk. You'll learn tips and techniques Jeremy used to make over a million dollars as an affiliate marketer.
When you buy the ebook you get a BONUS feature: the forums. Jeremy personally posts on the forum, answering questions. I've never seen another author provide such a quality forum. You won't get flamed on this forum. It's very friendly to new affiliates and a great way to learn.