So I've been playing around with GIMP for the first time recently, and I stumbled across RobA's GIMP tutorial (the pdf, not the thread). Since I've been trying to make a decent archipelago map for some time, I thought it would be worth giving it a go. I'm not sure I've really done the mountains right, I couldn't figure out deserts (not that they would really be appropriate at this scale), and I'm not enthralled with the color/density of forests or the color of the rivers. But otherwise, I think it turned out good for a first time!
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I have little to no experience with GIMP or PS, so pretty much everything here was done by following the tutorial to the letter. I'm not a huge fan of the text tool in GIMP, and I gave up pretty quickly there, since I have plenty of other things to work on. So any explanation of actual software processes might have to be dumbed down a bit so I can understand them