Ruby Users Guide
This guide covers the following topic: What is ruby, Getting started, Simple examples, Strings, Regular expressions, Arrays, Back to the simple examples, Control structures, Iterators, Object-oriented thinking, Methods, Classes, Inheritance, Redefinition of methods, Access control, Singleton methods, Modules, Procedure objects, Variables, Global variables, Instance variables, Local variables, Class constants, Exception processing: rescue, Exception processing:ensure, Accessors, Object initialization and Nuts and bolts.
Author(s): Mark Slagell
NA Pages 
Ruby Programming by Wikibooks.org
This book is currently broken down into several sections and is intended to be read sequentially. Topics covered includes: Notation conventions, Basic Ruby, Ruby Semantic reference, Built in Classes, Standard Library.
Author(s): Wikibooks.org
NA Pages
I Love Ruby Get started with the greatest programming language made for humans
Ruby is an easy to learn programming language. This book describes the fundamental concepts and techniques in greater depth than traditional introductions.
Author(s): Karthikeyan A K
NA Pages
