Texture sheet for a 3d object

First of all: Hi! I'm 16 years old and i'm new here:wave: My problem is how can I make a texture sheet for a building that I want to export to ADE. I've been looking for tutorials. I saw a pdf that explains everything very good except the texture sheet. At least I don't understand anything there. So if someone could explain me how to make a texture sheet it would be super!! I use Sketchup, Paint.net, and ADE. Also FSX SE. I don't know if there is another post asking the same but I searched and I couldn't find anything.


Iago Cao:)