Lets say I was writing an e-book that people would read on the net. Forget whether people would read it or not . At the end of the book I have a list of resources. Now I would only put resources in here that I believe will help my readers. However some of the resources use affiliate marketing, would it be wrong to use these links? Maybe I should mark next to the link that its an affiliate link.
you don't need to mark them as affiliate links. affiliate links are not illegal. just place them in a keyword contextual text.
Actually the affiliate links may help you, as long as the sponsors allows you to include it, feel free to add them. Depending on the nature of the book, you might want to consider adding a chapter or segment in the book about affiliate marketing. If your readers are out to make money, perhaps that would help them too and everyone is happy. It does not cost them more to buy from the links with or without the affiliate ID.
There are many people who make money distributing free ebooks with affiliate links embedded. There's nothing wrong with doing it, so long as you are recommending quality products and services. Preferably products/services you have personally used, but that's not always possible. Bottomline is, does your recommendation add real value to the person reading it? If yes, its fine to do it (unless the affiliate program terms forbid it...which is unlikely.)
"This is your affiliate link. You may not advertise, distribute or publish your affiliate link commercially, it's for your own personal use only."
If you use your affiliate links in a book they paid reasonable money for, it won't look professional For example www.seobook.com If you were selling something like www.zero-to-fifty.com, sure fill her up with them