Polys for straight, square surfaces, Nurbs for rounder more organic things.
Poly- walls, windows, doors
Nurbs-bannisters, doorknobs, handrails
You'll get to know what you want to use as you work more with them 
Darkon
Red bellows of flame have blackened my stones
Convulsing my frame and cracking my bones
Hell's dragons of steel who roar in their chains
Crawl into my caves to suck out my veins.....
-The Mountain P.F.M.