How do I start working on a map?

[Midgardsormr]

Thanks for the welcome guys

Thanks for the advice, though what do you mean by a scatter-brush? I only have Photoshop CS2.

It's been a while since I looked at CS2, but I don't think this information has changed much since then: Select the Brush tool (or I guess the Eraser in this case), and call up the Brushes window (Windows > Brushes or F5). There should be a list of settings categories on the left, and the second should be Scattering. Select that, and the checkbox should automatically tick. In the properties that appear, you'll have controls for Scatter, Count, and Count Jitter. Play with all of the controls there and see how they affect the brush shape. Scatter will give you a brush that creates randomly broken lines, and it can be useful to brush the edges of a mask or alpha with a scattered brush to create some breakup in it. I like it for the fringes of forests.