Documentation:
Ruby on Rails Documentation Page
http://rubyonrails.org/docs
APIs, books, tutorials, manuals,
 

 

 
Useful Links:

 

 
Training:
Pragmatic Studio: Rails Training
http://pragmaticstudio.com/rails/index.html
Rails Studio is an interactive workshop that combines the fundamentals taught in the book Agile Web Development with Rails with the trainers' collective experience developing and deploying real-world, commercial Rails applications.
 
Core Ruby on Rails: Web Development With Ruby on Rails
http://skillsmatter.com/menu/60/course/114
This hands-on, practical 4-day Ruby on Rails training has been developed by Chad Fowler, a software developer, author, and long-time leading contributor in the Ruby community.
 
Mr. Neighborly's Humble Little Ruby Book
http://www.humblelittlerubybook.com/book/
Free pdf download