As you may be aware, Google created a book database, including generous excerpts of most author's works. On October 28, 2008 the Authors Guild, the Association of American Publishers and Google announced the landmark settlement of Authors Guild v. Google.
If your books are available at google.com/books, you might want to go to the lawsuit settlement page, and fill in your contact information. That's how you'll be notified and compensated for any copyright infringement.
Read more about how the settlement works here.