Amateur Astronomer's Guide to the Deep-Sky Catalogs

Every amateur astronomer has at least heard of the many different catalogs of deep-sky objects; the most well known are the Messier, the Caldwell, the Herschel, and the NGC.  All of these catalogs are, in general, readily available, but very few amateur observers are in a position to choose the best catalog for their particular deep-sky observing program, know how to use the catalog, or even reali...