Russ Olsen - Eloquent Ruby
CHAPTER 1: Write Code That Looks Like Ruby
In the Wild
Absolutely the best way to learn to write idiomatic Ruby code is to read idiomatic Ruby code. The Ruby standard library, the lump of Ruby code that came with your Ruby interpreter, is a great place to start. Just pick a class that interests you; perhaps you have always been fascinated by the Set class. Find set.rb in your Ruby install and settle in for some interesting reading.