Book

Books are crafted from paper and currently serve no gameplay purpose except in crafting. Books and paper can naturally occur in chests, inside strongholds.

History
Books were added in Alpha 1.0.11. Their only use was to make Bookshelves, which was used as a purely decorative block. As of 1.9 pre3 (officially released in version 1.0.0), a book is also used to make an Enchantment Table, and bookshelves to boost its power.

As of development snapshot 12w17a books are now editable. An editable book is separate from the simple "Book" and is known as a "Book and Quill". It is craftable by combining a feather, a regular book, and a ink sac in a crafting table in any arrangement.

Crafting
Books are crafted from three paper sheets in any arrangement.

Note: In Snapshot 12w17a and later, books also require a piece of leather in one of the empty slots. The items can be arranged in any order, allowing books to be crafted without a crafting table. This is said to release soon

As a Crafting Material
Note: Books and Quills are crafted in any arrangement, and can only be crafted in Snapshot 12w17a and later.