How do I load a map? I download them and then unzip them...but don't know how to load them!

Wrong forum :p contact a moderator to move it :)

I think you just go to the Civ-Content (which is a dumb name, I don't get) option in the main menu, and as long as you've got the map in the right folder, it should be there.

Place the map in the following folder:

...\Civilization III\Scenarios
...\Civilization III\PTW\Scenarios
...\Civilization III\Conquests\Scenarios

depending on which version you have.