SculptrisA 3D modeling software that was recommended by a colleague.  Free download should do the trick for most school requirements.  Paid version for all the professional tools.
MAYAI like this free 3D modeling software platform.  A lot of tools and a bit more complicated to use.  Paid version with more professiional tools.  Suitable for our needs at senior high level.
CURA3D Printing software used by a variety of 3D Printers.  We use it with our Printrbot.