im new here too, as you can see.
theres a tutorial on some programs, and i think it depends on the kind of maps you are looking to do.
myself, im in "old school" maps, so i used yeasterday the Dungeon Crafter, a very simple "point and click" program, but it does not make a "realistic map", but those like this:
about dungeon crafter, i found this version very good:
and at Dragonsfoot web site, you can downlaod the old school blue pattern.