Looking at Duke's and Kaiser's modding guides, I feel like Kaiser's is pretty vague if you're not already familiar with this style of modding, and Duke's focuses too much on kpf files. You really shouldn't be modifying game.kpf directly, and you shouldn't be making your own until you're ready to package up a mod for release.
So I've thrown together my own basic modding guide for getting started. It explains what dev mode is for, and gives an example of the workflow for overriding files and making changes to them. I'll probably explain making kpf files and the mods folder later, possibly even in a separate tutorial to keep this one as simple and clear as possible.
I'm also moving the links to this stuff to my signature, so I can easily update them in one place if I ever reorganize my dropbox.
Rok, let me know if this helps you with getting started, and if anything isn't clear. Really what it comes down to is pretty much just getting the file structure figured out, and then opening stuff in notepad and experimenting.
Perhaps next I'll give a bit of an overview of what all the different files actually control.
