Here is an easy way to use Pinterest to build interest in your books.
Pinterest lets you easily create groups of photos to share with others. I think everyone enjoys viewing pictures. Sometimes I look through randomly selected groups of photos just for the beauty I might find. The nice thing about Pinterest is that the photos can come from the Internet. You don't need permission since the photo will link to the site where you found the photo. There are some places that don't allow sharing of their photos, but Pinterest knows which ones they are and you won't be able to pin those photos to your board.
How can Pinterest help author?
If your book is not yet published, create a board for you future readers. If you're writing a cozy mystery, for example, create a board called "My Favorite Cozy Mysteries." Your photos could be book cover images and you could add a short note about each book and why you selected it. After your book is published, one of the prominent pins on this board would be your book.
While writing The Vengeance Squad Goes to England I created a board with photos of locations and items used in the book. As I wrote the book, I added additional photos for each new scene. This served two purposes. First, the images helped me describe the scenes more realistically. Secondly, once the book was published, I included a link to the board so the reader could see photos of the places described in the book. See http://goo.gl/B6UFcX to check it out for yourself.
Another Pinterest board I made was one called Bookmobiles. The reason for this board is that bookmobiles are featured in each of my books. You may think of a similar use of Pinterest for your books. See http://goo.gl/NEXeZO for the bookmobile board. While you're there check out the rest of my boards for other ideas.