If you are looking for decent free software that you can use for creating maps, I am not too sure you can beat Gimp and Inkscape. These are the open source versions of Photoshop and Illustrator respectively. I know we have some tutorials for Inkscape and Gimp is very well supported in our Tutorials forum. I also suggest that you start WIPs (Work In Progress) for any maps that you are working on. You should get a lot of help through the C&C that the Guild can provide.