The Ruby Programming Language  (English, Electronic book text, Flanagan David)

This book directly starts with various keywords that probably may not be known to a beginner but if you know at least a little bit about programming in Ruby then you're in luck because the book is quite detailed with enough comments and citations to help you understand better. But before buying this book refer to couple of beginner tutorials over youtube or Net-tuts they will help a lot in understanding the book as well as Ruby. I would refer this book to anyone who wants to get into Ruby.
An...

This is a nice book for ruby.Every Ruby developer needs it increase their proficiency in Ruby Programming Language.So this book is very much necessary to master Ruby

its a good book to start with ruby basic syntax and semantics. This book will guide you through the datatypes & objects,expression, operators,ruby platform, meta programming,ruby environment n lots more. :) its a must buy.

O'REILLY has been one of ma fav.