How to delete books (epub) off your Itunes library

I'd like to remove some books from my Itunes library to make syncing with my Ipad easier. Some of the books are duplicates or (after reading) are not something I'd ever read again, so I'd like to delete them from the Itunes library. I can't seem to find a way to select one of these books and delete it. Any ideas on how I can do it? Thank you.

Hstio