Even though rather easy to built, my models were not designed for absolute beginners. They require you to at least have a basic knowledge of paper modelling. Also they are not "foolproof", so use your head while building them.
I tried to make the instructions as understandable as possible, but I still recommend you to download pictures and a 3-sides view of the aircraft you want to build, to check how things look when in doubt. The photos in the gallery to each model can also be used as a reference.
Check material for my recommended materials and tools.
It's up to you, how much detail you want your model to have. Some of the detail is not required to build a recognizable and good-looking model. Important difficult parts come in two versions, so choose the one that suits your skill. For Beginners, I recommend not to build the smaller details, since if one isn't good at building them, the model can be easily messed up by glue not going where it should. The landing gears are also somewhat tricky. Don't decide to build them open, if you are unsure if you can manage to build them: The gear well openings, once cut open, will look strange without landing gear. When in doubt, build the landing gear before cutting the holes. Small parts that are easily lost or ripped are printed two times, so don't be surprised, should there be leftover parts.
My models don't feature dashed lines to show which lines have to be scored, so carefully check, which tabs have to be scored and which don't. tabs, which are used to glue together a round part onto itself, such as on fuselage parts or wheel treads, are not scored. tabs in landing gear wells are often bend inward after scoring, which should be mentioned in the instructions.
Some parts should dry a little after glueing and before being glued to the next part, especially the landing gears and the parts of the engine. The instructions don't take that into account, so use your best judgement. With models that have more complicated paint schemes, such as lines or camouflage, it's important to watch that the paint scheme fits. Every version has been tested to fit.
Cockpit kits for aircraft models:
The cockpit kits for the aircraft models are the small detail which make a nice aircraft model even more impressive. But be aware, that for most of them, building them in the original scale can be quite challenging. To avoid frustration, better avoid them or scale up, which leads me to...
As all models are 100% vector-based, they can be scaled to any size lossless. This means curves and graphics will never blur or pixelate. Of course at a larger scale design inaccuracies become more obvious. And of course you may also adjust the paper thickness accordingly, as the models were designed for 120gsm paper in their original sizes.
If you aim for a certain scale, you may find this useful:
Scale calculator (thanks to Zarkov models for making this available)