Getting Ruby for Mac

I was working on a project with a friend and needed to get Ruby on Rails for my mac, and this was an incredibly helpful tutorial to do so. here. I would like to add that if you get the error

Can not find compiler and 'make' tool - make sure Xcode and/or Command Line Tools are installed.

, in order to get command line tools (assuming you've downloaded Xcode) do the following: go to Preferences>Downloads, and click install on the row for "Command Line Tools". After this, you should be all set! Note: it'll take awhile. 20-30 minutes is my estimate?