I have a Mac OS X with Snow Leopard 10.6.4 that has Ruby 1.8.7 preinstalled from the factory. I have zero experience with Terminal and programming, but I am trying to learn Ruby and want to upgrade to the latest version 1.9.2. I have tried various methods in books, on the web, Locomotive, etc. and I just cannot figure out how to get it installed and configured as the default. The resources on the web for this keep losing me at various technical details. Can anyone provide detailed, step-by-step instructions for how to do this for an absolute beginner? I would like to have all the ancillary programs like Rails, RadRails, gems, etc. as well. Thanks very much for any assistance.
P.S. On the current version, I also cannot get Shebang, the Tk toolkit (which is factory installed), or the "sprintf" command to work.
P.P.S. How can I change the default directory that Terminal looks for programs in? Right now it's under my user root directory but I don't know how to change to another default folder I'd rather use.