I teach the third required intro course in a CS department. One of my homework assignments asks students to speed up code they have written for a previous assignment. Fact
If you are looking for something that is really really esay to set up, then why not go for the free SVN hosting option, you don't have to set up a thing!
Sadly the two older ones that everyone would have pointed you to being Assembla, Unfuddle, have dropped support for their free hosting ( or at lest if you want them to private ), but you can still use Origo this give you both open and closed hosting.
The advantage of this is that you can own all the projects and follow them all, and easily control the people who have access, and you don't have to worry about right for creating repos.
If you do go this route, and you want to eliminate complexity then you must use a GUI svn application to make learning near trivial ( since I doubt there will be much merging going on ). I would recommend tortoisesvn, slips right into your windows explorer context menu.