What would be the best (free) software to try my hand at some map drawing? I am mainly interested in fantasy type map drawing for table top role playing games like AD&D. I am looking for something that is easy to use as I get my feet wet but will still produce a map that doesnt look as if it was drawn by a 3 year old with Crayons. As I get a bit more experiance I might step up to a program that has to be bought but I would like to stick with something that is free at first.

Thanks in advance