As we talked about yesterday, pork is divided into large sections called primal cuts. Pork primal cuts have all kinds of peculiar names, like the Boston butt, which is nowhere near the butt, and the picnic shoulder, which you would never bring to a picnic. These primals are then broken down further into individual retail cuts — the roasts and chops you buy at the store.
Anyway, here's a great video that illustrates the various pork primal cuts, including where each one comes from, along with some ideas for how to prepare each one. You'll even find out what to do with the head.