.Map :: MoHAA Mapping

Im trying to make a ncie skybox, but i cannot find a nice sky textures, so I had to create one. I made the texture, but where do I put it? also, my map has no light! I can add multiple light entities but that is just not practical, how do I add ambiant lighting?

you guys have been a most EXCELLENT help!

my first map! i made lots of nice terrain with plenty of hills and nice textures, now how might I add trees and shrubbery to give it a nice woodsy feel?