Not long ago one of my room mates ending an argument with his girlfriend by punching a small hole in the wall of our living room.
No fear, we went to our local Mallow's Hardware store and asked the friendly staff about how to patch the wall. He showed us the equipment we needed (spackle, putty knife) and gave us some basic instructions. Went home and followed his advice, the wall looks (almost) as good as new! Great experience at Mallow's.