There are several ways to do this and the level of detail varies between different companies but yes, I would think that is a good idea.
It may help you to decide which method suits you best, if nothing else. I also recommend a search right here. You'll find several discussions about process mapping.
A good place to start IMO is with Dianne Galloway's workbook, "Mapping Work Processes", ASQ Quality press ISBN 0-87389-266-6. In no way a definitive scholarly book on the subject but a great, easy to read, fun, inexpensive introduction to mapping using everyday examples.