You really need to read the User's guide first. It's not that big.
Ok, I'll look at it again.
A wall is ... a wall, not siding. You can set a baseboard on a wall with a given thickness to represent siding or you color/texture the wall itself. If you want to physically add a separate siding you add either a second wall or other objects to function as siding but this will unnecessarily complicate your design. Since you need the holes the best way is to use the existing wall and texture the outside as siding. If your siding has a thickness you add that to the thickness of the walls. Remember that Sweet Home 3D is not a CAD program, it's for house and interior design, the max precision is 1mm.
I will experiment with using a 'baseboard' on the exterior then. It is very tedious and it requires me to make adjustments to the walls because some of them are not appearing in the 3D model even though I'm looking directly at them in 2D. I can see this taking me an inordinate amount of time to do one colour scheme. Maybe it would be faster and easier to print up a bunch of copies and colour them in with coloured markers.
For changing the colors or textures of multiple objects there are two plugins you might find useful: General Change Texture Plugin and Change color. The easiest way to install them is to first install the Plugin Manager plugin . Direct download (v1.5.3): PluginManager
This is what happens when I try to download Plugin Manager:
You can manage Watches in your profile to get notifications. One should automatically be set if you don't uncheck "Watch this thread".
It says I'm watching this thread, but I still don't get any notifications. I even logged into the website of my email account to check the spam and junk folders and settings, but there is nothing from SH3D in them.
