Bram Cohen's Practical Cryptography

Maybe someday Schneier will write a book which I can recommend to people who are getting started in cryptography, but I'm not holding my breath.

Schneier wrote Applied Cryptography, which is the best way to get started in the field. I picked it up while I was still learning programming (and not exactly confident in my math abilities) and still found it incredibly well written and understandable.

http://www.schneier.com/book-applied.html

From the Preface:

"I wrote Applied Cryptography to be a both a lively introduction to the field of cryptography and a comprehensive reference work."