ko155,
Thanks for your service. Do yourself a BIG favor and purchase the book at the link provided. It is an engraving course in itself. It will teach you almost everything you would learn in a formal basic engraving course....except you won't have the benefit of having someone explain things in person. It is geared to exactly what you want to do, and unlike many books is step-by-step with accompanying pictures and drawings in simple, easy to understand language.
http://www.airgraver.com/Engraving-H...-Schippers.htm
Dave