Beginner Books

• Agile Web Development with Rails Edition 3
• Build Your Own Ruby on Rails Web Applications by Patrick Lenz

Advanced Books

• Advanced Rails Recipes: 84 New Ways to Build Stunning Rails Apps, by Mike Clark
• The Rails Way
• The Ruby Way by Hal Fulton

Free eBooks

http://freecomputerbooks.com/langRubyBooks.html

But, I would also suggest you check out these other free resources which keeps up to date with the technology.

Screencasts and Podcasts

• Railscasts by Ryan Bates – http://www.railscasts.com
• Learning Rails – http://www.buildingwebapps.com/podcasts
• Peepcode Screencasts – http://www.peepcode.com

Learning Sites

Ruby Learning Hub – http://www.rubylearning.org/class/ by Satish Talim. They have a lot of free courses on various subjects but one should do the Ruby course first.

Magazines

Rails Magazine – www.railsmagazine.com

Top Blogs

• http://www.loudthinking.com/ by David Heinemeier Hansson (creator of Rails)
• http://www.rubyinside.com/ by Peter Cooper.
• http://mephistoblog.com/ by Rick Olson and Justin Palmer
• http://hivelogic.com/ by Dan Benjamin
• http://redhanded.hobix.com/ by _why the lucky stiff
• http://nubyonrails.com/ by Geoffrey Grosenbach
• http://errtheblog.com by PJ Hyett and Chris Wanstrath
• http://www.slash7.com by Amy Hoy
• http://weblog.rubyonrails.org by the Rails core team
• http://weblog.jamisbuck.org/ by Jamis Buck
• http://www.railsenvy.com/ by Gregg Pollack