[Saulot]

As to the difficult parts, I pretty much concur with Endoperez.

My suggestion to make things easier is to carefully examine other nation mods. There are plenty of good ones to choose from, and each may have something cool or new to educate you in modding ways.

There are also a couple of things which make a modder's life easier; The dom 3 database (To examine different weapons and units, and if you plan on copying already existing unit sprites), Or a graphic editing program (if you plan to make your own unit sprites) such as GIMP.

On a slightly different note, if there truly is no 'modding for dummies' tuturial, and the information available is insufficient, and there is demand, I'd be willing to contribute towards one (though there are others better suited to the task).