There's no shortage of useful documentation, tutorials and blogs for you to read, but these sites stand out as being worthy of note:
- The official guides are where I tell programmers who are new to Rails to start; the quality is very high. See http://guides.rubyonrails.org/.
- If you fancy giving yourself a full tutorial, the Pragmatic Programmers have it covered in their book Agile Web Development with Rails.
Once you've got started, these are very useful:
- Railscasts -- regular screencasts from Ryan Bates demonstrating how to achieve specific tasks in Rails.
- Rails Recipes -- a book by Chad Fowler that contains plenty of worked examples, covering many common tasks encountered by the practicing Rails developer. Updated for Rails 3.1.
Oh, and if you're not yet familiar with Ruby get acquainted before you start learning Rails (I've listed some useful resources on my Ruby page). If you don't understand Ruby syntax you'll have trouble separating the language from the framework, and that really slows you down.