How to take care of an iPod touch with a broken screen?
Unless you are going to never flex the device, you'll want a clear adhesive cover or clear tape to prevent the glass from easily falling out and cutting your fingers or lying in wait in a pocket or bag.

Something like a Otterbox case with a more substantial plastic barrier might be appropriate (or even both clear tape and a thicker plastic sleeve depending on how likely the glass is to fall out.

If you run your finger nail lightly over the surface, you should be able to tell if the underlying layers are cracked or if the surface digitizer layer is cracked and proceed appropriately.

In cases where the digitizer is intact, I have known people to baby a phone for 6 or more months without any glass pieces falling out, so it really depends on how bad your drop was.