Some additional references:
Steel Bolt Hacking by Douglas Chick - a good how-to guide, specifically aimed at computer hackers.
lockpicking101.com - a decent forum for discussing technique, tools, and tricks of the trade.
lockpicks.com - a reasonably-priced gear outlet. (Note: please familarize yourself with any applicable state and municipal laws before purchasing lockpicks. In New Jersey, for example, it is illegal to carry lockpicks
with the intent of using them to commit a crime. Of course, if you're in a position where the cops are already rifling through your stuff, having a set of lockpicks on you is probably your least concern

).
You can also do a Google for "MIT's Guide to Lockpicking", a free PDF by an accomplished hacker - a slang term for someone that can lockpick (used long before computers came along).
I'm just starting to get into it. The basics are ridiculously easy to understand (99% of what you need to know to pick a lock can be explained in 1 or 2 paragraphs), but damn hard to master (hours and hours of hand cramps and frustration).