First, if you're not sure on how Ruby and Ruby on Rails differ, the first paragraph of the Wikipedia article sums it up fairly well.
Ruby on Rails, often shortened to Rails, is an open source full-stack web application framework for the Ruby programming language. Ruby on Rails is not to be confused with Ruby, which is a general-purpose programming language, on which Ruby on Rails runs.
We also have an article about the differences between Ruby and RoR here on Codecall, along with other assorted Ruby tutorials.
Ruby on Rails Guides, including Getting Started with Ruby on Rails.
Alternatively, learn Ruby in 20 minutes. The guide does assume you're starting with Ruby already installed.
Tekniqual has a set of Ruby video tutorials covering basic Ruby programming including loops, conditions, strings, etc.
10 useful Ruby on Rails tips for developers. Aimed at mid to high level programmers, not beginners. The same site also offers a history of Ruby and Ruby on Rails, which leads into a beginner tutorial (part 2 here).
10 more useful Ruby on Rails tips. These ones are aimed at beginners.
Ruby News is a Twitter account dedicated to keeping developers updated on Ruby advancements. Tons of useful links here, not for beginners though.
Ruby Inside has provided Ruby and Ruby on Rails tutorials since 2006. Site is in blog format.
A reference sheet for Ruby is provided here, although the most recent update was 2011. Also available as a download.
Tutorials Point has a collection of Ruby resources and tutorials.
Everything you need to use Ruby on Rails in one package. Alternatively, download Ruby by itself with RubyInstaller.
Aptana Studio 3, a Ruby aware IDE.
Be sure to post any other good Ruby resources you know of!