here. Once you make a new map you can add mountians, lakes, vallys, hills, etc. using the brushes under the highth tab. The nature tab controls the weather and atmosphere. If you go under the objects tab you can navigate to a object, to add it all you need to do is have it selected, adjust your options, hit shift, and move your mouse to wearever you need it and let go of the mouse key. Finally under the texture tab you choose a texture and paint it.