2 things that really got my Ruby going were 1. creating a project that
was around Ruby rather than Rails which is not huge, but gives me scope
to use a lot of different aspects of the language. 2. Reading David
Blacks Ruby for Rails, it is so clear in explaining some of the
underlying facets of Ruby.

On this thread very near the bottom;

http://groups.google.com/group/ruby-talk-google/browse_thread/thread/cc5c6e8bb05fb31a

David Black lists a number of items that should be understood about
Ruby, it is a pretty good list and you would find yourself a good step
forward by trying to learn about each.

James