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Ruby/Ruby on Rails
By an Amazon.com customer
Beginning Ruby: From Novice to Professional (Beginning from Novice to Professional)Beginning Ruby: From Novice to Professional (Beginning from Novice to Professional) by Peter Cooper
Buy new: $26.39 / Used from: $23.64
Good book for beginners - get started here...
The Ruby Way, Second Edition: Solutions and Techniques in Ruby Programming (2nd Edition) (Addison-Wesley Professional Ruby Series)The Ruby Way, Second Edition: Solutions and Techniques in Ruby Programming (2nd Edition) (Addison-Wesley Professional Ruby Series) by Hal Fulton
Buy new: $29.69 / Used from: $23.00
Must have - next step after Beginning Ruby.
The Ruby Programming LanguageThe Ruby Programming Language by David Flanagan
Buy new: $26.39 / Used from: $19.50
New - Another must have - covers Ruby 1.9.
Programming Ruby: The Pragmatic Programmers' Guide, Second EditionProgramming Ruby: The Pragmatic Programmers' Guide, Second Edition by Dave Thomas
Buy new: $29.67 / Used from: $22.95
A classic, but I'd get The Ruby Way and The Ruby Programming Language first.
Ruby Cookbook (Cookbooks (O'Reilly))Ruby Cookbook (Cookbooks (O'Reilly)) by Lucas Carlson
Buy new: $31.49 / Used from: $9.52
The Perl Cookbook is a great book from O'Reilly. I'm glad to say that O'Reilly has a winner to as well.
Agile Web Development with Rails, 2nd EditionAgile Web Development with Rails, 2nd Edition by Dave Thomas
Buy new: $26.37 / Used from: $16.99
Where everyone starts, but a little out of date.
The Rails Way (Addison-Wesley Professional Ruby Series)The Rails Way (Addison-Wesley Professional Ruby Series) by Obie Fernandez
Buy new: $31.49 / Used from: $25.00
A must have...not an intro book, but definitely will deepen your knowledge or Rails once you've got a few project under your belt. Includes Rails 2.0 coverage.
Advanced RailsAdvanced Rails by Brad Ediger
Buy new: $23.09 / Used from: $17.00
Well written and very useful. Would put this in my top three favorite Rails books.
Advanced Rails RecipesAdvanced Rails Recipes by Mike Clark
Buy new: $22.67 / Used from: $20.89
It's not out, so I haven't seen it, but I'm guessing this will be another must have.
Rails Recipes (Pragmatic Programmers)Rails Recipes (Pragmatic Programmers) by Chad Fowler
Buy new: $21.75 / Used from: $11.95
Must have - it's a bit out of date, but filled with great recipes.
RailsSpace: Building a Social Networking Website with Ruby on Rails (Addison-Wesley Professional Ruby Series)RailsSpace: Building a Social Networking Website with Ruby on Rails (Addison-Wesley Professional Ruby Series) by Michael Hartl
Buy new: $29.69 / Used from: $25.00
I like the Addison-Wesley Ruby/Rails books. Pre-Rails 2.0, but I found this to be one of the best books to start with.
Build Your Own Ruby on Rails Web ApplicationsBuild Your Own Ruby on Rails Web Applications by Patrick Lenz
Buy new: $26.67 / Used from: $11.84
A great book for newbies, another good book to start with...however, like a lot of Rails books at there at the moment, it's pre-Rails 2.0.
Rails Cookbook (Cookbooks (O'Reilly))Rails Cookbook (Cookbooks (O'Reilly)) by Rob Orsini
Buy new: $26.39 / Used from: $3.71
Another good recipe book.
Pro Active Record: Databases with Ruby and Rails (Pro)Pro Active Record: Databases with Ruby and Rails (Pro) by Kevin Marshall
Buy new: $24.43 / Used from: $3.75
Mixed reviews - I found it to be a good beginners book (not pro) and a nice reference.
RESTful Web ServicesRESTful Web Services by Leonard Richardson
Buy new: $26.39 / Used from: $11.98
Highly recommended. Not Ruby/Rails specific (but does use Ruby for many examples).
Ajax on RailsAjax on Rails by Scott Raymond
Buy new: $26.39 / Used from: $14.98