So one of the hardest things to do in a highly dynamic language is to debug code. If you feel the same way, check out the ruby-debug gem. Rails 2.0 now has full support for it and it’s a real “step forward, into, and out” debugger.
Here’s a great screencast to get you started. If you use cheat (which I highly recommend), simply type cheat rubydebug in the console to see all the options.