The http://rubyonrails.org/down site is really self-explanatory. First you need to download Ruby (and by the sounds of things, you have) and install it.
Next step is to get rubygems(version as of this post is 0.9.4). Extract that zip file and you should have a directory called rubygems. Open up a command prompt window and navigate to be inside that directory and then run ruby setup.rb. This will install RubyGems for you.
The final step is to install Rails. Now that you have RubyGems you should be able to type into the command prompt window "gem install rails --include-dependencies" which will not only install Rails, but all it's required dependencies like ActiveRecord (how it talks with the database) and so on. To set up a Rails application skeleton type "rails <app name>" where <app name> is the name of your app. Then go into that directory and type "ruby script/server" and this will start your Rails server.
The book should explain the rest. Welcome to Rails.
Last edited by Radar (2007-09-26 21:27:58)