Ebook: Rails Recipes (Pragmatic Programmers)

Rails Recipes is a great way to get accustomed to Rails-specific idioms and to incorporate many of the basic features used in dynamic web applications today. Unfortunately, much has changed in Rails since its printing. Many of the recipes are outdated. For its time, though, it was the best all-in-one collection of Rails tips. From what I understand there's a new version coming, but I don't know for sure.

The Pragmatic books are generally good, but I've come to prefer the Addison Wesley series on Rails and Ruby, which are thorough and up to date.