How to make maps?

[Skolem]

Thanks a lot, maybe I should precise my problem.
In my actual state I have draw a white map with only the border on it, it is a precise map that I want, the problem is I haven't found a picture with a high enough resolution on the web, so I hoped I could simply "improve" one founded. But it seems to me that if I wanted it played (and I see no point in creating a map of which I know that even I wouldn't play on it) it has to be better than provinces with 1 color (green for forest, brown for mountains etc ). So my problem is that I have a "blank" map like the one you could make with DomMap, what I want are "pretty" forests and Mountains and so on...
Actually I tried to "steel" the trees of a Map made by Targa to paste them on my map with Photoshop, but it didn't function like I want it.

If GIMP is even harder to learn as Photoshop, then it is sadly definitively not the application for me.
Did Targa made his Map with GIMP? (if yes I bow before his skills and knowledge, his Map are definitively the best avaible for dominions actually )

I'm sure there should be some Mapmaking programms who could do exactly the types of Maps ones want for dominions with with tree's mountain's, swamp's and so on preimplemented, any clue were one could find them?