I just got a mac book pro and was thinking I would try my hand a ruby and ruby on rails I have installed rails with sudo gem install rails four different times because no one says to be in a certain dir when you start the install. I do which rails and get Rails is not currently installed on this system. To get the latest version, simply type: I have tried adding to the path where gem says rails is and I have restarted the whole computer still no luck any help would be great. I used the video on Lynda.com followed from the beginning so I am not sure whats going on.
That's because it doesn't matter. 
What is the output of `sudo gem install rails` ?
What is the output of `gem list --local` ?
What is the output of `gem env` ?
https://github.com/thoughtbot/laptop
This pointer takes you to a project with a couple of scripts that should setup what you need. It'sa polished and maintained set of scripts for installing ruby on rails on a mac.
Best of luck! -kevin
@kbedell