Here I am collecting some of the good resources to start learning rails, specially rails 3. Before starting learning rails - a ruby framework, it's always better that one should good little familier with ruby language.
Ruby Intro -
To know about ruby in short and fast way - http://rubylearning.com/satishtalim/tutorial.html
This tutorial can help you get started fast.
Ruby in deep -
To dig deeper in ruby language this is nice book to read - http://www.ruby-doc.org/docs/ProgrammingRuby/
Rails intro -
For rails 3, to get introduction about rails 3 and it's structure refer to rails guides - http://guides.rubyonrails.org/
These are official rails guides and are kept updated constantly.
Rails 3 quick introduction video series - http://rubyonrails.org/screencasts/rails3
Rails 3 video Tutorials - railscasts.com - This has always been a very great resource for all rails learners. This is video blog with many of commonly required tasks covered under 8-10 minutes of video tutorials. To specifically see rails 3 tutorials, you can select rails3 tag there and start from first. I personally found this site very helpful.
For deeper reading, you can review Michael Hartl's Ruby on Rails tutorials. This is considered to be one of the best free online tutorials for rails 3.
To know everything about rails 3 one can refer to bible of rails i.e. - Agile Web Development With Rails 4th Edition.
Rails other references -
Rails 3 in netshell - http://rails-nutshell.labs.oreilly.com/
Collection of some very good links and videos regarding rails 3 - http://railsnotes.com/rails-3/
An article with many rails 3 reading material links - http://mediumexposure.com/rails-3-reading-material/
If you some other better resources, please post them in comments.