First off I'm a beginner at affiliate marketing. To be honest I didn't even know what it was before I joined there. Basically it gives you the rundown of everything you need to know about affiliate marketing. It even gives you two free wordpress based sites/blogs to use. There are tons of videos and discussion groups to get you started and answer any questions you may have. The best part is their owner is really hands on, and will try to help you along the way. The second best part is that its all FREE!! It goes over how to choose a niche, basic seo, monetizing your site...ect..ect.. There is a premium membership, but you don't need it to have access to all of the good stuff. There is a more advanced course for more experienced people, but the free stuff is fine with me.
There aren't very many negatives about this service, at least none that I have found so far.