I took an absolutely fabulous class at Creative Side Academy here in Austin t0 learn PMC. It was a great introduction to this medium. Basically this is silver impregnated clay that you shape like modeling clay. After firing in a kiln, the organic binder burns off and you're left with pure silver. This is great for charms and small pieces of jewelry, although if you have a larger kiln and the money for a lot of packets of clay, you could probably get larger pieces. I definitely recommend either taking a class from an experienced instructor (vs. an artist trying to make some side money who is just going to get you really frustrated when you get into the more advanced stuff) or investing in a few good books on Precious Metal Clay and networking with other DIY PMC'ers in your area.
Here are the three pieces I finished in class. We used PMC3, fired in a kiln, cleaned with steel wool, and polished (and work hardened) with steel shot in a vibratory tumbler. Great fun and I love to wear these!!