Ruby for Rails

Ruby for Rails is a good one too. I haven't read it though. http://www.amazon.com/Ruby-Rails-Techniques-Developers/dp/1932394699

I have to second this. "Ruby for Rails", I feel, is a great resource for learning not only the Ruby language, but how to program with it. It really did not need the Rails section. I've only flipped through "Beginning Ruby" (apress), but that looks like a good Ruby book too.

"Ruby for Rails" by David A. Black is a good choice if you're new to Ruby as well as Rails. It spends a lot of time on Ruby fundamentals and only brings in the Rails stuff after having explained the necessary bits of the language so that it actually makes sense. I read the Agile book first, and as a Ruby newbie, it gave me only a very vague understanding of the language. R4R did a much better job of that.