Ruby Hacking Guide
by Minero Aoki
The RHG is a book that explains how the ruby interpreter (the official C implementation of the Ruby language) works internally. To fully understand it, you need a good knowledge of C and Ruby. This book is going to investigate ruby as a whole.
Home page url
Download or read it online for free here:
by why the lucky stiff
This is just a small illustrated online-only Ruby book. It won't crush you. It's light as a feather (because I haven't finished it yet--hehe). And there's a reason this book will stay light: because Ruby is simple to learn.
This book is a great collection of ideas, tricks, and skills that could be useful for Hackers. It's a unique extraction reference, summarizes a lot of research and experience. Rubyfu is a book to use not only to read, it's where ruby goes evil.
Everything from installing Ruby and the basics of the language through to topics such as arrays, file handling and object-oriented programming are covered. Written both for experienced in other programming languages and for novices.
by Michael Hartl - Addison-Wesley
Leading Rails developer teaches Rails 3 by guiding you through the development of your own complete sample application using the latest techniques in Rails web development. Hartl explains how each new technique solves a real-world problem.