So, I've made some more progress this morning:

11TopRightMountains.jpg

12MidlandValleyBed.jpg

13MainPeninsula.jpg

14LandFin.jpg

The final shot shows pretty much how the topography (correct word?) of the land will be, there is some touching up of most of the landmasses to do and the water hasn't really been touched yet.

This is my first map so I'm still learning a lot of the process of doing things but I think it's looking pretty good so far.

There are a couple of things I'm unsure about: I'm not sure I'm a massive fan of the river mouths and I'm unsure how to colour the lower right portion of the map. The area is supposed to gently transition into plains, possibly showing a hint of a desert further inland (and to the right).

I'm also still not quite sure on scale either, the widest rivers are roughly 5 pixels across, any ideas how wide that would probably be? (I'm guessing there are quite a number of things to consider here)