[Gandalf Parker]

Check the screen sizes of your monitor or various softwares. Those are good to go by for a map that looks good on the screen. For my maps I tend to use 1600x1200. But it also depends on how many provinces you are trying to put into it since too much crammed in causes the images to blur. I find that 150-250 provinces tend to meet most peoples needs.

Also the game will try to fit any map onto your screen but the Width/Heigth will affect the file size greatly. A 200 province map on a 4000x2000 map will be incredibly detailed and zoomable, but it will take forever to download if you are letting the server send the map to each user. On the other hand those same 200 provinces squeezed into a 800x600 map might be ugly and pixilated.