Here's a list of Ruby references, along with my comments.
Wikipedia Intro: Ruby (programming language)
Official site: http://www.ruby-lang.org/
Excellent intro on Ruby. 〔Wikebooks: Ruby Programming @ http://en.wikibooks.org/wiki/Ruby_Programming〕
Written by Matz, translated. 〔Ruby User's Guide By Matz. @ www.rubyist.net…〕
〔Programming Ruby: The Pragmatic Programmer's Guide by Dave Thomas, with Chad Fowler and Andy Hunt. @ www.ruby-doc.org…〕
〔〈Ruby Programming Language〉 by David Flanagan. amazon〕 probably the best, by the same guy who wrote 〈JavaScript the Definitive Guide〉.
Official. 〔Core Reference http://www.ruby-doc.org/core-1.9.3/〕
Official. 〔Ruby 1.9.3 Standard Library Documentation @ www.ruby-doc.org…〕
RubyDoc.info, seems a comprehensive site for Ruby library documentation. http://www.rubydoc.info/
Wikipedia Intro. Ruby on Rails
Official site. http://rubyonrails.org/
Not so good. But a quick start to guide you in installing Rails and run it. 〔Getting Started with Rails @ guides.rubyonrails.org…〕
A very verbose book. 〔Ruby on Rails Tutorial: Learn Web Development with Rails By Michael Hartl. @ ruby.railstutorial.org…〕
Official Rails API doc. http://api.rubyonrails.org/
Rails Searchable API Doc @ http://railsapi.com/
Others, i haven't used yet.
http://apidock.com/ruby [with user notes]
Chinese book. 〔Ruby on Rails 實戰聖經:使用 Rails 3.2 及 Ruby 1.9.3 By Ihower. @ ihower.tw…〕
Video. 〔Rails Casts China: #013 Live Show with Ye Dingding 1: Dingding 展示如何写一个简单的在线聊天室。第一期主要是展示如何实现 backend 和写测试。 By Ye Dingding. @ railscasts-china.com…〕