The Essential Blender Guide is the latest book covering features up to Blender 2.45. This book starts with a quick tutorial to get you started with Blender. The Blender Gamekit is aimed at people who want to learn to use Blender's real-time engine, as opposed to rendering stills or animations. There are also books for Animators and people who are interested in the Physic features of Blender.
All books are available in our E-Shop.
Online documentation of Blender can be found here.
There are many community-driven discussion boards where you can ask questions, or give answers related to using Blender. See the Help Forums section of this site for more information.