TJ,
Engraving is an advanced skill. By your question, it appears that you are not familiar with it. There are great videos and books on the subject if you decide to pursue it. GRS is the main source for this info and many of the items needed. One caveat is that it tales considerable time and practice to get even moderately proficient at it. The equipment is also fairly expensive. The best way to learn hand engraving in the shortest time would be to go take the GRS course. It is offered at many different places, including the Moran School of Bladesmithing.
Carving on wood and sculpting on metal is an alternate method that is simpler and can be done by untrained people with some artistic talent. If you can draw a good looking design or initial with a pencil on the knife handle or bolsters, you can probably carve it is. The tools are usually a high speed handpiece or micro-motor, and carbide burrs. The basic flex-shaft setup and some burrs can be put together for $400-500. Fancy micro-motor tools could take that to $4000-5000, but that is for more professional people.
To just try it out, a good Dremel and some small carbide ball burrs will suffice. It won't duplicate the results from the better tools, but it will work to try it out. You will probably also need small needle files and sandpaper. Tiny pieces of sandpaper can be used to smooth up the details and are pushed by sharpened chop-sticks. Cratex wheels and points are also good for finishing.
A starter project would be to carve an initial in some scrap wood, and if the results were good, to do the same in a handle. Next try it on a piece of brass, and if the results are good, do it on a bolster.
In all cases, it starts with a pencil and your hand.