Hey Elijeh!,
The best advice I can offer is to get hold of a good graphic design program and experiment. A good one to start out with might be Microsoft Image Composer. It's the one I use for my bit maps. It will allow you to do all the neat effects you see like parchment oceans and cool shorelines.
You can pick up a copy at:
http://rx7.cyberosity.com/gallery/misc/MS_Image_Composer/
- OR -
http://www.softseek.com/Graphics_and_Drawing/Graphics_Viewing_Editing_Painting_and_Conversion/Review2_6762_index.htmlHopefully, those two sites still have it for download. If not, simply do a search for "Image Composer" on the web.
Good luck on the campaign!
- imhotep