I recommend installing Ubuntu on a separate partition to avoid upgrading issues later on:
Then completing this Rails tutorial:
Then expanding your knowledge with RailsCasts while developing your own web application:
Then completing this Rails tutorial:
Then expanding your knowledge with RailsCasts while developing your own web application:
http://www.groovypost.com/howto/create-virtual-machine-hyper...
It's a lot easier just to dedicate one to school work and dispose of it when done, or clone it another VM is needed.
That way Ubuntu is just another app.