Which part of map gen are you looking for help on?
Creating the landscape to use in the game should be in the map gen thread.
If you are looking for help in making the image to make into a map, then I can give you some pointers on that.
First, you will need a paint like program (originally, scracc (sim city region and city creator) but that has been lost to time). I would recommend HME (Height Map Editor) from here
. I recommend this one because you can set custom map sizes (like the 386x386 needed for lomo maps).
Second, you'll need a steady hand and patience. Start off simple, then go to more complex designs.
Hope any of this has been helpful. I potter around the forums most days, so if you need more help just drop a pm my way.
Just to help you out, I'll include the height charts that I put together. For reference, in the png height chart, the locomotion heights are on the left, while the heights to use in hme are on the right (sorry the notation on it is a bit messy but it shouldn't be hard to understand.
Oh, If your interested in a map (atleast to test with), I have a map here
. Nothing too fancy, but hopefully helpful.