The graver is simply a piece of metal that has been hardened, shaped and sharpened to a point and angle. The graver's shape, as well as the angle at which the engraver holds it, determines the furrow's shape. An engraver may choose from many different graver shapes, but most prefer flat- and v-shaped gravers. The flat graver has a flatened tip, while the v-shaped graver has a tip ending in a v-shape. If the engraver uses a graver alone without any helping device, she will hold the graver stationary while feeding the item to be engraved along the graver's tip.
Even engravers who prefer the hand-pressure method may use a small wooden handle to hold the graver steady. If the engraver prefers the the hammer-and-chisel method, he may use a rotating vise or similar instrument to hold the item being engraved, leaving his hands free to control the graver's path through the chosen metal with the hammer.
Working according to the same principle as the hammer-and-chisel method, pneumatic gravers use air-pressure to move a self-contained piston. The piston, held within a graver handpiece, applies pressure to the graver, allowing the engraver's free hand to maneuver the item to be engraved.
You can find many engraving supplies online, as well as forums in which you can ask questions and receive answers regarding the tools. Many large and specialty crafts stores also carry engraving supplies. Look in your local business telephone book for nearby shops.