If you haven't gotten it yet get Lisa's terrific ebook,
The Perfect Site Guide. It is a great book, well worth reading for many reasons, but particularly relevant to your question.
It is a great example of how to use an ebook that you give away free. By encouraging others to give it too it can get a lot of coverage. In it she does a number of things that help achieve just the results you are looking for.
It does include a number of affiliate links, just as you would have on your site. But there is much more. For example, you can refer to additional material on your site or blog (or You Tube or anywhere else you can link to), and by doing that you can build additional traffic to your work elsewhere where you can sell your products.
You couldn't find a better model. So I would study it carefully as a model as well as reading it for the valuable content.