Honestly, if you're planning on focusing on Rails eventually, I'd start with the Rails Tutorial by Michael Hartl (http://ruby.railstutorial.org). It's easy to get lost as a total beginner with all the various things Ruby itself is capable of, when you might have better results focusing on a smaller subset of the whole, at least to start. Rails tutorial also has a chapter early on (one of the first five) that contains an intro to ruby and can point you in the right direction from there.

Book-wise, you can't go wrong with The Well-Grounded Rubyist (http://www.amazon.com/The-Well-Grounded-Rubyist-David-Black/...) to begin with. I found it a lot more approachable than the Pickaxe book early on.

Good luck, Ruby was my first language and I learned a lot about learning programming languages from that experience.

If you have previous programming experience, I don't think that it matters much. You can always look stuff up as you go if you already know enough to know what you're looking for.