Before I spew, I need some more constraints. (sorry!)
What era/age/tech level are we at and what style civilization is this? Is this circa 600 CE northern European, circa 1200 CE southern African, next week's northern American or what?
Are you looking for a total creation, or using an established map?
How in depth are we to go? Do you want an entire website with something akin to the Silmarillian, or is a long post of about 1000 words overkill?
Thanks for the challenge!!