The Pragmatic Programmers book on Rails is very good and already updated for Rails 4. If you get through it and still want more, the Rails Way is the most comprehensive book I've seen. Railscasts is great once you are making apps on your own as it tackles small specific problems.

Don't forget about the official Rails guides themselves, they are actually quite helpful.

I go back and forth on whether learning Ruby first is best. You will learn more about Ruby itself just by solving RoR problems, but I think you would solve them faster if you already had a solid base in Ruby.