Hi Edgewalker, and welcome to the Guild!
If you are comfortable with pen and paper, and are interested in digital enhancements, I would suggest first investing in a scanner, and just downloading GIMP as an editing package. You will be able to scan in your art then colourize/combine/edit digitally... I believe another newcomer, Absinth, posted examples like that here.
Another is example is a map I made a while back, here.