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 Zed A. Shaw - LCodeTHW
The book assumes absolutely no prior programming knowledge and will guide you carefully and slowly through the learning process. When you are done with it you will have the skill to move on to other books about Ruby and be ready to understand them.
by Avdi Grimm - objectsonrails.com
The book is documenting some guidelines and ideas for applying classic object-oriented thought to Ruby on Rails applications. It is aimed at the working Rails developer who is looking to grow and evolve Rails projects while keeping them flexible.
by Huw Collingbourne - Dark Neon Ltd.
A straightforward introduction to the fundamentals of Ruby programming: strings, numbers, objects, methods, class hierarchies, arrays, iterators, hashes, modules, mixins and much more. Small, self-contained programming samples are included.
by Gregory T. Brown - O'Reilly Media
Ruby Best Practices aims to help Ruby developers from a wide range of skill levels improve their fundamental understanding of the language via exposure to the common practices and idioms that many seasoned Rubyists take for granted.