Looks like I finally found somebody to test whether our guides really are beginner friendly
Basicly, ZModeler saves the location of textures, either folders containing seperate images such as png or dds files or complete ytd archives. Additionally, it's possible to set up folders that will always be used, I use that for vehshare textures for example. This can be set up in ZMod's configuration (little icon next to the edit button on top) under Services. I usually keep all my textures in a folder that I add before importing the model. You open the texture browser as shown in the guide, click "Add..." and select your textures (or even a complete .ytd).
As soon as you select one of those textures, ZMod will remember this folder. When you import a model, it'll look for all textures in those folders with the same names as those included with the model and add them to the Texture Browser. Alternatively, while importing, you can set specific preload packs as mentioned in the guide to either automaticly use all .ytd files in the folder of the .yft or specific files.