Also, tell them it would be great if they offer the book from their site or mention it in their newsletter. This is viral marketing at its finest. Your next step should be to add a page on your site where visitors can download the book. If you have any graphic skills at all, whip up a book cover to add along with a description that stresses the benefits they'll receive from reading it. Make sure you put them on this page as well.
Testimonials are very powerful.
If you publish an ezine you can use the book as a bonus for your subscribers. There are many other ways to promote your new book. Contact ezine publishers that you think would be interested in your subject matter and send them an e-mail stating how nice it would be if they mentioned it to their readers. Most publishers are always looking for content and will be happy to help out. Some websites do e-book reviews and then publish them online or in their newsletters.