Tips for supervising interns
My biggest piece of advice is set expectations from day one and then work with them very very closely until you feel like they have "taken off" and are also on the same page.  It is such a short amount of time that you may have to have them do some shadowing to get them on board as soon as possible.  

The worst thing you can do is tell them to do things, not get what you expect, then in week three you have gone no where, you are frustrated, they are frustrated, and then they are gone before you know it.