New here, as the post count will probably suggest, but I have taken an interest in doing my own cartography for a Role Playing Setting I am building. I had been using a free online resource to make my maps, but after finding some awesome Tuts here, I have decided to give it a try myself.

Background: Computer Engineer by trade, older in years, prefer Linux at home (so looking at using GIMP, but a novice user), have had some art training (years ago)... blah blah.

Anyway, the question. Did I mention I have ADD and OCD? The question, right... I want to make some base elements/brushes and wondering what size I should go with so that they scale well and look good big or little? Also, not sure how to change the dpi either. What dpi, once I figure it out, should I start with?

Thanks before hand,
The Bane