Sounds like either your computers don't have enough processing ability to handle 3ds Max, or the scene you are rendering is (to put it simply) too fancy. To help with this, try reducing polygons and try using materials that are not overly detailed. As nice as it may look, it makes it hard for the computers. Shorter scenes also help.
As for rendering, go to the Rendering dropdown menu and select "render setup".
This will give you a window that will let you change how much you render. (The time output section I think is what you should be looking at)
I hope this helps!
If not, let me know.