Use the Index Luke

Use The Index, Luke is a free guide to SQL performance for developers.

Unlike many other SQL performance tuning resources, Use The Index, Luke avoids unnecessary details about database internals but highlights the most important topic for fast SQL: proper indexing.

http://use-the-index-luke.com/

Little Brother

Little Brother is a book written by Boing Boing's author Cory Doctorow.

The book is available here: Little Brother in multiple formats.