Once you have your world(s) built and characters to roam the realms, wouldn't it be nice if those weary wanderers had a place to get in out of the weather? I'm talking temples and taverns, inns and dungeons, castles and markets, TOWNS!
Here's several useful sites I've saved over the years:
Medieval Demographics Calculator
Medieval Demographics Made Easy
Green Pilgrim's Town List
http://www.inkwellideas.com - Random Village Generator
http://www.inkwellideas.com - Random City Generator
http://www.rdinn.com - Town Generator