@Ascension: as you can see on the tutorial images, there are only 2 or 3 real satellite images in my texture. I use images of marble, wood and rocks, and I blend all of these several times to obtain good relief and figure the landscapes I had in mind for the final map.
Most of these textures have the same saturation and an uniformisation is necessary to get a texture which will be colorized with the background. Of course, the difficulty is to keep color differences to obtain the color effect you've seen. Finally, I put my texture layer on Overlay (Incrustation), and it blends with the color layer.
@Katto: I could translate the entire tutorial to make a .pdf file and share it on C'sG. It will take time, and, as Aelyn said, PS tags require me to take a look at an english version of Photoshop, even if I remember some of the english equivalences (thanks to Blender!). Just be patient
@Reckless: I used basic brushes of Photoshop for this map. The mountains are in a layer with Pillow-Emboss style effect. Little hills are any spongy brush you can like, with few opacity. Bigger mountains require some sharpened brushes blended with spongy effects. My mistake was to begin with the Hyrule mountains. You can see on the entire map, that I drew too large mountain ranges. As a result, they looked like rock shelves till I reduced and erased with smooth brushes. But erase some zones with a 30% opacity rubber several times between two mountain drawings is a good way to figure many details in your relief.