Fix version indicator on guides and link to Rails 4.0 [ci skip]

guides/source/_welcome.html.erb

@@ -10,10 +10,13 @@
 </p>
 <% else %>
 <p>
-  These are the new guides for Rails 4.0 based on <a href="https://github.com/rails/rails/tree/<%= @version %>"><%= @version %></a>.
+  These are the new guides for Rails 4.1 based on <a href="https://github.com/rails/rails/tree/<%= @version %>"><%= @version %></a>.
   These guides are designed to make you immediately productive with Rails, and to help you understand how all of the pieces fit together.
 </p>
 <% end %>
+<p>
+  The guides for Rails 4.0.x are available at <a href="http://guides.rubyonrails.org/v4.0.4/">http://guides.rubyonrails.org/v4.0.4/</a>.
+</p>
 <p>
   The guides for Rails 3.2.x are available at <a href="http://guides.rubyonrails.org/v3.2.17/">http://guides.rubyonrails.org/v3.2.17/</a>.
 </p>