Unless you go the customized route for decals, you can purchase N scale decals to help decal your rolling stock, bridges, buildings, or locomotives. I usually find my N scale decals at train shows. There is always someone clearing out their N scale decals of what they have left or will never use.

I've read lots of advice, howto, intro, and helpful things on the internet about modeling railroads.

But nowhere is there any information for the beginner, [ ... ]

I've finally added as much plaster cloth as I expect I'll need, and have moved on to priming the base before painting it.  Priming made it look unfamiliar, [ ... ]