A model's ID in the URL is not very helpful to the user. Consider adding the name which can also improve SEO. Learn how to override to_param, add a slug attribute, and make a catch all route for deep nesting.
Do you ever wonder what goes on behind the scenes when a Rails controller handles a request? What do the "render" and "redirect_to" methods do exactly? This and more covered as we walk through the code of ActionController::Base.