Book

Books were added to Alpha in the Secret Friday 6 (v1.0.11). Books are crafted from paper and currently serve no gameplay purpose except in the creation of the decorative bookshelf block. However, in a recent tweet, from Notch, he states that readable books will exist in the future.

Crafting
Books are crafted from three paper in a vertical row.

As a Crafting Material
Books can be combined with wooden planks to craft bookshelf blocks.