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 
This page covers the following topics related to Ruby : The Fundamentals, Installation, Tweet Fetching, Style, Conventions, and Debugging, Numbers, Strings, Variables, Methods, RubyGems, If and Else, Loops, Collections, Enumerables, File input/output, Reviewing Tweet Fetching, Supplementals, Design and Theory, The Projects.
Author(s): ruby.bastardsbook.com
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
