Ground Textures

How can I use ground textures (dirt, rock, round tiles) on a building or doodad?

so.. like have a burrow that looks like its made outa mud? its skin editing, i would say get the skin you want to edit and the textuer you want to put on it, then copy n paste the texture over the building's skin, then import it into your map

Well duh, but where do you find the dirt texture?

Open up the MPQ and look under Terrain Art.