Literature

Books

• Russ Olsen: Eloquent Ruby
• David A. Black: The Well-Grounded Rubyist
• Paolo Perrotta: Metaprogramming Ruby: Program Like the Ruby Pros
• Yehuda Katz and Ryan A. Bigg: Rails 3 in Action
• Jose Valim: Crafting Rails Applications: Expert Practices for Everyday Rails Development

Online materials

• Ruby @ Wikipedia (http://en.wikipedia.org/wiki/Ruby_(programming_language))
• Ruby Best Practices (http://rubybestpractices.com)
• Read Ruby 1.9 - ebook with a lot of examples (http://ruby.runpaint.org/)
• Ruby on Rails Guides (http://guides.rubyonrails.org)
• Railscasts - screencasts about Ruby on Rails (http://railscasts.com)