Chet and Ron have been working with Ruby, because it's the nearest thing there is to Smalltalk. Here are the books we use.
In this review: Programming Ruby, The Ruby Way, and Ruby in a Nutshell.
This is the first Ruby book, by the justly well-known authors of The Pragmatic Programmer. Much of the popularity of Ruby in the English-speaking world is surely due to this one. It's very well-written, quite free of errors, and the personal style of these fine -- if very different -- gentlemen comes through.
Programming Ruby is available in downloadable form: Chet and I use the Help version when we pair program in Ruby. We feel that you are morally obligated to purchase a hard copy in addition to downloading. (We could be wrong, we frequently are ...).
Hal's book is bigger than Dave and Andy's, and it is a bit more current. Hal digs deeper into "Ruby Style", and very much deeper into specific ways to do things.
When you need a bit more of a leg up on something than you can find in Programming Ruby, Hal's book is the place to look. We have used his examples of network programming to figure out things for generating this web site.
Less-experienced programmers will profit from Hal's examples and discussion as well, with his focus on programming in "the Ruby way".
“Matz” is the author of Ruby, and this is his book, translated from the Japanese by David L. Reynolds, Jr.
The book is subtitled “A Desktop Quick Reference,” and that’s just what it is. It lists all the language basics and built-in library, with the method names and short descriptions. Kind of a pocket guide, though you’d need a big pocket. When what you need is a reminder of what objects have which methods, this is the one.