Half of this is just for personal reference so I don’t forget where stuff is. I was having a hard time deciding where to start, so I figured I would research first..now, onto the links!
Medieval Demographics Made Easy (Generator for that info!)
Something a little more scientific
For Scifi, but still seems interesting
Solar System Builder (if you’d like to be realistic!)
Edit: Really awesome looking cartography forum that I found via the Wired blog about making worlds. Very cool stuff! Cartographer’s Guild
