Good Rake Tutorial

“As a Rails developer you’re probably familiar with running “rake” to run your tests or maybe you’ve used “rake db:migrate” to run your migrations. But do you really understand what’s going on under the hood of these Rake tasks? Did you realize that you can write your own tasks or create your own library of useful Rake files?”

http://www.railsenvy.com/2007/6/11/ruby-on-rails-rake-tutorial