Someone recently suggested I look at bookbub.com for free and/or discounted books for the Kindle and other e-readers. I don't know if "real" books are offered, but you enter your favorite genres and receive a daily list of books. This has been a great way for me to discover new authors and interesting books for a minimal cost. Bookbub suggests the books, but you go directly to Amazon to purchase. (I'm just a happy customer, not in any way affiliated with either website!)