There are several ways to start on the field files...
One way to start is to set the fieldscene in your background in the perspective viewport (Alt-b in Max)
create a plane (it helps if you know the dimensions) and match it up with the floor (perspective) add the walls and off you go.
once you've placed the planes, you might make them transparent (alt-x) so you still can see the background.
after that create all the objects, and place them correctly in the scene.
The way SL and several other started, was doing it in sketchup, there is a possibility to set a dimensional grid to match the camera to the field image.
You can also project the image through camera mapping on a plane, but that's a bit more difficult I think.
You might also want to take a look at camera matching tutorials within max itself.
I hope this helps you a bit on your way.