I use Valve Hammer and it does work. I've created a couple of maps that run, and I think I've got it mostly figured out....
Some things to remember:
You must put lights in your map. LOTS of them - if you rely on the default lighting that QRAD puts into a map with no lights you will have a pitch black map. This sounds like what is happening.
Make sure you have NO leaks.
Keep it small and simple to start. TRUST ME on that...
Run QRAD or your textures will appear all rainbowed.
Turn on some white fog. That will help you see the walls in the dark. You can always remove it after your testing.
Finally, if Valve Hammer reports ANY errors, find 'em and fix 'em. Half life might be able to get past them but your DBPro creation will not.
Hope that helps. Good luck and just be patient with it. It took me a good week to figure it out.
The Lemac
"Just wut the Sam Hill is a dadgummed leemack anyhoo?"