When photographing jewelry one of the best ways is to make a studio box..or light tent. It can be as simple as a cardboard box with the sides cut out.
Cover the back,top and bottom with white paper, tape or spray glue works well. Here the side openings are shown and the back has white paper taped in.
Next a back ground sweep is created with a piece of charcoal paper taped at the top and allowed to curve. You could tape the front edge to the box flap or leave it loose. Add two pieces of tracing paper or thin nylon cloth over the side openings. Place a light fixture like a desk lamp with a flexible goose neck on each side with a CFL lamp daylight balanced on each side. and you are ready to shoot.
This is shot in this box. My light source is a bit larger as is the light tent itself....this box construction was shot inside my light tent. And I used my lighting to light the ring through the sides of the box.
This is my studio box 40 inches wide and tall, with two umbrellas reflecting light into the interior. You can see an extra light for sparkle on the right side. It is hand held with a clear glass bulb inside.
This setup came from Amazon most of it is Cowboy Studio brand and is overkill for small pieces. The light bulbs are 100 watt CFL's in daylight color. For a box under 36 inches one light on each side is sufficient.
This set up is available http://www.amazon.com/Table-studio-lighting-5000K-daylight/dp/B002PNEDFS/ref=sr_1_10?s=electronics&ie=UTF8&qid=1364139818&sr=1-10&keywords=light+box+photography and would be ready to go out of the box. I use a tripod always and always a remote release. If you shoot with a simple point and shoot camera a tripod and turning off the flash will be best. The result from the shot taken in the box is identical to what you would get with a more sophisticated light box, but you need to use a gray background if you can not adjust the settings in your camera. A white background is often seen in some jewelry shots but it requires adding 2 f-stops of light to the base exposure or in the case of compact cameras use the "snow scene" setting. The idea behind this whole project is to provide even clean shadowless illumination to reveal the details of your jewelry. There are many other setups that can work but this is easy, repeatable and not dependent on weather or time of day.
The bigger the box the more room there is for props and for reaching in to set up the shot. I shoot ceramics and jewelry and some days shoot 125 pieces. Having the box setup works for me. This is just an overview....ask questions about specific setups and I can do my best to help out.