[thedevelopment]

The Rails Way is pretty good.

http://www.amazon.com/Rails-Way-Addison-Wesley-Professional-...

I've found the peepcode webcasts worth their weight in gold, but that's not a book =)

And I found Design Patterns in Ruby pretty good for Ruby beginners

http://www.amazon.com/Design-Patterns-Ruby-Addison-Wesley-Pr...

http://peepcode.com/

[luminary]

Thank you, sir.