Agile Web Development with Rails (The Facets of Ruby Series)
Dave Thomas, David Hasson, Leon Breedt, Mike Clark, Thomas Fuchs, Andrea Schwartz
Order from Amazon
Programming Ruby: The Pragmatic Programmers’ Guide, Second Edition
Dave Thomas, Chad Fowler, Andy Hunt
Order from Amazon:
Ruby in a Nutshell
Yukihiro Matsumoto
Order from Amazon:
The Ruby Way
Hal Fulton
Order from Amazon or InformIT:
Sams Teach Yourself Ruby in 21 Days
Mark Slagell
Order from Amazon or InformIT: