The best book I have found already on the market is "Kickin' Bot" by Grant Imahara. From the small amount of text in his book I have read so far he was once on a FIRST team.
I found it about a month ago at Barnes & Noble only to come home and find it on Amazon.com for $10 cheaper.
I was going to post on this book sooner, but I have not really had much time to do so.
I have only had time to flip through it, but there are many diagrams and great tips.
It appears to cover everything from tapping threads to drivetrains; however, this book was made for battle robots, but most of the same principals and ideas apply to FIRST robots!
If anyone is intersted here are some links:
Price: $16.46
http://www.amazon.com/exec/obidos/tg...books&n=507846
www.kickinbot.com