Never store any of your gear, especially your nylon harness and rope in direct sun light, and keep them clean. Make sure to always follow the manufacturer's instructions on proper care. With this sport more than any other, it's important to be an expert in your equipment and your safety procedures. Seek out as much information and experience as possible. The information on this site is provided as an overview, and covers only the basic equipment needed for top roping.
Lead climbing has a whole spectrum of other equipment.
The standard harness is made of nylon webbing. The straps run around your waist and your legs. Harnesses all look about the same, but there are two typical styles. One has separate leg loops and the other is more of a diaper style. The leg-loop harness is the most common, using a belay loop to attach the legs and waist straps.