Is there a guide to Rails for experienced Rubyists?
The rails guides are by far my favorite resource!
http://guides.rubyonrails.org/
I would recommend The Rails 3 Way for a good introduction to Rails at both a high level and fine grained details, without the "Welcome to Programming" tone.
I just got this one, and it looks really good so far:
http://pragprog.com/titles/jvrails/crafting-rails-applications