There are two fantastic resources I came across detailing what's new in Ruby 2.0, the first of which
and there's another with many examples that's a bit more verbose.
Installing Ruby 2.0 was quite painless for me; I'm on Mac and have homebrew installed, it's certianly much easier with than without.
rvm get head && rvm install 2.0.0
This should end up spitting any brew related errors; you'll have to install those missing libs and simpy run the command again to compile
ruby-2.0.0-p0 from source.