Welcome to the Guild Lordfly! Well Inkscape is certainly a good start. I've seen some lovely work done with it. There are one or two Inkscape tutorials that I'm familiar with (have a look in the Tutorials section at the Sticky "Tutorials in PDF Format"). You might find something useful. Well, all the best on your new project. Be sure to upload pics of your WIP map once you get started. You'll get some good feedback that way.

Cheers,
-Arsheesh