First of all you never want to chisel with a dull tool. It's a good idea to keep a fine grinding wheel close by to keep your chisel in good working condition. Or you can keep a metal file handy and use it to sharpen your chisel. However, you must be extremely careful when sharpening your chisels, if you place more pressure on one side of the file or sanding wheel, than the other side you risk making the chisel lopsided and useless. Some do it yourselfers prefer to simply buy a brand new chisel when the one they have gets too dull. It depends on how skillful you are with a file and whether or not you want to keep the tool or throw it out and buy a new one.
Never use a wood chisel for anything other than cutting wood. For harder materials you will need a cold chisel or a masonry chisel. A wood chisel is beveled on one side only; the cold chisel is beveled on both sides.
Be sure to use a wooden or plastic mallet to drive your wood chisel. You'll need a metal mallet for the cold chisel. If you use a metal mallet, which is far heavier than a wooden or plastic one, to chisel through wood you run the risk of ruining the wood because you will be striking the chisel with too much force.
Be sure to always wear proper eye protection whenever you work with either one. There is always a good chance of either wood or masonry breaking off and landing sharply in your eye if you don't wear goggles.
Here is some more information concerning chisels.
Wood Chisels are woodcutting tools. Instead of just buying one chisel or two, you may want to consider purchasing a set of chisels ranging from 1/4" to 1 1/2" in widths for general use.
Socket chisels are supposed to be used with a mallet. Though some experts prefer a hammer.
Tang chisels are for working with the weight of the hand only. For more specialized use, purchase a good beveled-edge
Cabinetmaker's chisel is for finish work.
The square edge of a framing chisel is best for framing work, while the narrow mortise chisel serves to break waste away.
Tips on Chiseling
1. Start your blade digging into the wood, slightly inside your guideline mark.
2. Do not cut too deeply. Chisels are meant to chip and shave away. The beveled edge goes into the work so that it constantly directs the chisel out of the wood for better control.
3. Keep the cutting edge directed away from your body and hands.