Foundation Rails 2

That would be: Ruby on Rails Power!: The Comprehensive Guide by Aneesha Bakharia. Its currently rated 2/5 on Amazon. For my 2 cents, I'd second both of Peter's suggestions - Foundation Rails 2 and Simply Rails 2 - though I do tend to like the former a little more. The latter is better if you have absolutely no prior web dev or programming experience.

The main thing you want to do when learning Rails is to make sure you're pretty solid in Ruby. David Black's Well-Grounded Rubyist covers a lot of Ruby. As for Rails, I have nothing but good things to about Foundation Rails 2 by Eldon Alameda. He gives a brief introduction to Ruby at the beginning, and doesn't rely on scaffolding/plugins, something a lot of early Rails developers try and overuse. Although, now that I think about it, the routing chapter was a little weak. Of course there's also the standard Agile Web Development with Rails (3rd Edition) which was written by the creator of Rails. After that, the best place is to start writing apps and get some hands-on experience. If you want, there's another book that Eldon Alameda wrote called "Practical Rails Projects" which does exactly that -- guides you through 6 or 7 Rails projects to teach you all about Rails. However, it uses an older version of Rails (1.2.3 compared to the current 2.3.3) but I'm sure a lot of the concepts will still apply. You can always install an older version of Rails to follow along.

I own almost every Rails book in one format or another (I run a top Ruby blog so I get them to review) and... it depends what you're trying to do. The Rails Way kicks ass once you already know Rails to a certain extent - it's definitely not a first book. It's a "bible" type book and is stuck somewhere back in Rails 2.1 land, I believe, but most of it still applies. AWDwR is reasonable and mostly up to date (focused at Rails 2.2, as far as I recall) and particularly suited for people who are totally new to Rails. My recommendation for people who are new to both Ruby and Rails is Foundation Rails 2 by Eldon Alameda as it has a 30 page primer to Ruby included and spends a long time "touring" Rails. It also covers RSpec which, given you're Agile, might be of significant interest to you. Books I'd steer away from either because they're out of date or just plain bad IMHO would be all of the Packt books and Beginning Rails from Apress (the latter, hopefully, will be brought up to date in a 2nd edition).