These are Edge Guides, based on the current master branch.
If you are looking for the ones for the stable version please check http://guides.rubyonrails.org instead.
<% else %>These are the new guides for Rails 3. The guides for Rails 2.3 are still available at http://guides.rubyonrails.org/v2.3.11/.
<% end %>These guides are designed to make you immediately productive with Rails, and to help you understand how all of the pieces fit together.