I am writing a book that I want to make a map for.

I installed GIMP to make this map with.

I need a world map that consists of three different continents.

I am wanting to make a color map with 3-d ish looking mountains such as I have seen posted here. (such as the one made in RobA's wonderfull regional worldbuilding tutorial)

I have the basic shape/outline of one of the continents made.

Here is what I see as my problems so far. I am not making just a region but a whole continent. (That and I am trying to create a world map as my first project in GIMP that is)

I think I have a grasp on the basics in GIMP and from what I know, I am at a loss to figure out how to color/texture the land. (don't get me started on mountains)

The map has differnet regions that are of course different climates.

I can't just generate a noise layer and then auto color the texture and bump map it. That won't work. I need the different regions to have different colors and textures (and eleveations)

I can't just paint it with a wide brush and have it look like what I want it to.

How do I best go about this then?

Just how does one create a world map such as I am needing the encompasses jungles, deserts, temperate, etc, conditions?

How do you texture/color elevevate something like that?

What would be the method that I should go about to acomplish this?

Do I cut the map into segments and work on each segment and then somehow merge them all at a later date?

Do I select what I think each region will be and texture those and somehow blend them afterwards?

Do I somehow create layers of each regional climate and somehow piece them together at the end?

I have hand drawn a map, and I know what I want (mostly) and where I want it.

I am thinking about just cutting the map in 1/2 and only working on the northern for 1/2 now as the first book will only deal with this northern area. (I think)

I would rather do the whole continent all at once though.

I just don't quite know how to make it in GIMP with my limited understanding that I have of the program.

Suggestions, links, advice etc would be most welcome.

Thank you in advance.