In my opinion, Ruby for Rails is the best rails book. Way to few rails
developers know ruby well enough to do powerfull stuff - the real power
in rails lies in ruby.
I gotta second the imperative for learning Ruby. Rails is Ruby. Ruby isn’t [just] Rails but Rails most certainly is Ruby. The better grasp you have on Ruby’s wondrous bag of tricks the better you’ll be able to command Rails’ own special brand of magic.
In my opinion, Ruby for Rails is the best rails book. Way to few rails
developers know ruby well enough to do powerfull stuff - the real power
in rails lies in ruby.
It is an excellent book, and in my opinion better than pickaxe for learning Ruby with or without Rails, but for learning Rails you need Agile, otherwise you miss out on things like migrations and tests. Agile also covers the Rails material in more depth. Ideally, you have both, they complement each other superbly.
I say this from the perspective of someone who is currently using both books to come up to speed on Rails (and who is discovering that he really didn't know Ruby half as well as he thought he did :-))