“This is the book that everyone coming from another language to Ruby should have.
To fully realize the potential of Rails, it's crucial that you take the time to
fully understand Ruby—and with Ruby for Rails David [Black] has
provided just what need to help you achieve that goal.”
—David Heinemeier Hansson, creator of Rails, in the
preface to Ruby for Rails
Ruby for Rails: Ruby techniques for Rails developers was one of the first Rails books published, and quickly became a standard. "R4R" was written by David A. Black to help budding Rails developers acquire the Ruby skills they need to do Rails right. It's helped thousands of practitioners do exactly that.
Ruby for Rails is available directly from the publisher, Manning (you get a PDF with the paper version), as well as through Amazon and other online booksellers. Look for it in your local bookstore too! And see the R4R homepage at Manning for sample chapters, author's online forum, and more!