Welcome to the guild A. Smith! That's pretty nice for your first attempt, and we ALL thank RobA for all the time he has taken to product tutorial after tutorial after tutorial....etc Be sure to give him (and other people if you find stuff you like) rep for it. RobA is one of the result GIMP gods here... Also, you may want to look around as a few people (including Rob himself) have done some various tweaks on the techniques used and come up with some even better techniques.
And finally, post more maps soon. Post early post, often is the motto around here. Oh yea, the other motto is post bigger, higher res images.
btw, I really like your legends. very simple, yet effective. Nice font, what is that?
Joe