Well usually you can find a lot of downloadable ones online, I couldn't give you one on the spot, but to install one, you haave to download it, unrar it, then go to the start button in the bottom left corner, go to the run thingy, and type in %appdata% in there you will go to .minecraft then to saves, and the folder you unrared will go into saves. Open minecraft and load the world. Hope this helped.
yeah i have mcedit but how can make the whole world flat? sorry but im a newbie :unsure.gif: