Which CWNA book to start with?

Cat5

I'm about to jump into studying the CWNA and would like a recommendation on which book to start with? Is one enough?

I saw the book "CWNA: Certified Wireless Network Administrator Study Guide" which has different publication dates. The newest, 2012, is obviously the best, but it's also the most expensive. Would getting an older edition really make that much a difference (to someone like me on a budget)?

Frostbite

The earlier publication dates (and cheaper price) are probably because they apply to previous incarnations of the exam. Make sure you get a study guide that covers the PW0-105 exam.