The best place to create any link in ReaderLinks is on the book's page. Here's an example of how to create a link that goes to the Amazon Book Read page:
1. Go to the specific book's page on ReaderLinks
2. Click the Links tab
3. Click on the orange "Add New Link to This Book" button
4. Fill in the location where the link will reside (i.e. newsletter swap or FB ad)
5. On the "What page will it land on?" line, select "Book Read Page"
6. Fill out any other info such as affiliate codes or Facebook pixel id, etc. (not required)
7. Click the orange "Add Link" button at the bottom of the page
If you create a link like this often you should consider using an Automatic Link. Automatic Links allows you to create a link once and apply its functionality across all of your books.