Book- Getting Started with Arduino

If you've heard about this Arduino thing, but are unsure about where to begin, Getting Started with Arduino is a great place to begin. 110 pages of easy to read, well written, Make/O'Reilly goodness. Massimo Banzi (author and one of the 5 Arduino developers) describes the basic hardware, writes some simple programs, and explains how to use the free Arduino development environment.

Info:

• Getting Started with Arduino - O'Reilly Page
  
• ISBN 10: 0-596-15551-4
  
• ISBN 13: 9780596155513