I truly enjoy a good map myself. And with my addiction to table top RPGs where 99% visual content is must be acquired on your own, I have been learning to draw maps on my own.
I use photoshop, yes, but a program alone won't do the trick, Trust me, I have searched and searched and tried dozens of programs. Although I haven't though of trying the terrigan program, I have attempted to use 3DsMax, but the results take too much time to have a quickly useable reward.
My best advice is to practice. Study, and Learn maps. Google up some fantasy maps and spend hours looking over them. Go to google earth and look at the terrain and landscape for miles up. Look at the coastlines and the depth of waters.
It'll start to make sense after you make a couple dozen maps.