This peaked my interest so that I started looking at some of your other tutorial map thingies. It's really good stuff, and helpful too. I've never tried doing maps from any perspective other than straight down, so I might give it a try now...
Great job DJ. Out of curiosity, how long would you say you've been designing digitally/illustratively? I only picked up a digital tablet about 3 months ago so tutorials like this are great for improving my own developing style.