Ruby on Rails Tutorial

try ruby!
http://tryruby.hobix.com/
Try Ruby in your browser. A hands on Ruby on Rails tutorial.

Why's (Poignant) Guide to Ruby
http://poignantguide.net/ruby/
Guide to Ruby on Rails.

Ruby on Rails
http://www.rubyonrails.org/

Instant Rails
http://instantrails.rubyforge.org/wiki/wiki.pl
One-stop Rails runtime solution.

RubyCentral
http://www.rubycentral.com/
Get started with Ruby.

Ruby-Doc.org Documenting the Ruby Language
http://www.ruby-doc.org/
Help and documentation for the Ruby programming language.