At the
http://www.ruby-lang.org/ have found funny ways to start learning Ruby with examples and small code exercises, a very practical approach.
Ruby in Twenty Minutes has been an enjoyable start, also
Hackety Hack! that remember me
ProfStef from Smalltalk land.
Then I was ready to start with
The Ruby Koans, a way to look a little deeper in to the language driven by unit tests, great and funny !!!
After that I investigated more Ruby idioms,
http://cbcg.net/talks/rubyidioms/ &
http://stackoverflow.com/questions/613985/common-ruby-idioms, some of them related to more advanced or esoteric language features, that you would live perfectly without the 99.99% of the times and that can make the code hard to read and understand.
Still I feel the need to explore the boundaries of the territory to get more comfortable with a language and than stick with the easy to read features.
Update 18 August 2012
More Ruby idioms:
-
http://renaud.waldura.com/doc/ruby/idioms.shtml
-
http://devblog.avdi.org/2012/05/07/a-ruby-conversion-idiom/
Update 4 October 2012
Ruby conventions:
-
http://rubyist.info/