This technique will show you how to create square holes in your geometry. As a bonus, this will also detail how to add chamfer detail to the hole that will allow you to apply a turbosmooth or meshsmooth modifier while also maintaining all quad geometry.
If you are interested, you can also take a look at my other tutorial for creating circular holes in 3ds max.
The first image in the gallery shows the result of this tutorial. As you can see, this technique will allow you to create a clean square hole, which is great for window and door frames, picture frames, furniture, or cut out details on electronics and other man-made items.