Hi.
I've written a small tutorial on how to match up the lightsources in worldcraft/VHE with the nice landscape editor Terragen.
This is for you who allready know HOW to make your skybox using terragen. I'm sure there are tutorials out there for that. This, however, is something I had to find out for myself, so I'd like to share it.

Tutorial:
http://zetterstrand.com/cs/tutorials/calibrate.htm

de_priory: http://zetterstrand.com/cs/screenshots.htm