It takes you through building various demo apps, using ruby, rails (separately at times), git and heroku. It doesn't bog you down in too much detail or theory, instead it introduces ideas in bite-sized packets and then shows the code relating to the theory immediately. I'm learning rails 3 from it, without ever having picked up much of rails 2. Highly recommended. The guy who wrote it, Michael Hartl, was in YC too.
http://railstutorial.org/book
It takes you through building various demo apps, using ruby, rails (separately at times), git and heroku. It doesn't bog you down in too much detail or theory, instead it introduces ideas in bite-sized packets and then shows the code relating to the theory immediately. I'm learning rails 3 from it, without ever having picked up much of rails 2. Highly recommended. The guy who wrote it, Michael Hartl, was in YC too.