Okay, had some time to play with things a little bit. I read the responses to my last thread, and thank you all, it's a big help. But I now have two more questions:

1). I'm wondering if this isn't a problem so much as I'm using 8 and what I'm playing with is intended for, say, 11 or something more recent that what I have. I found a free Poser model with a bunch of accessories (figure, hair, armor, etc.). I decided to try to install manually, since, if I can grasp that, then the shortcuts will be much more intuitive since I will understand what is going on. I copied everything over the way I was supposed to, moving everything from the subfolders in the download into the folders in the Runtime on the desktop (please note, this is just an experiment to make things easier to find, I know I will have to put things in their proper place when things get serious).

On the bright side, it worked. I clicked Add Library, selected it, and everything is there. Figure, hair, props, everything. Just one thing missing -- color. The figure, props, etc. are all white instead of blue and gold like they should be. A couple of the clothing downloads had files at the top of the file tree, right next to the Runtime folder, so I moved them to the corresponding place in the Library file. But that doesn't explain why those that didn't have those files at all are still turning up white. I did a test render, because sometimes, like with my model of the Enterprise D, it shows up as white in the work area but a render shows it properly colored. Is there something I'm missing, do I have to find a way to color the model myself, or is the model intended for a more recent version of Poser and this is just something I'm going to have to deal with until I upgrade?

ETA: I only downloaded a couple of the prop files, one of which was casual wear. That is colored fine. The armor and such was its own file, not part of the figure download, and that shows up as white.

And as long as I'm on the subject, I downloaded another model supposedly for Poser. It's a low-res DVa from Overwatch. This thing has several files in it, 19 total, with names like 0.dae, 0.fbx, 0.mtl, 0.obj, DVa_D.tga, generic_item.mesh, and so on. There are no subfolders or README's in here. Is this not a Poser model at all (it was free, so it's not like I'm out any money if I got it wrong), or is there a way to create a library and put this in there? (It is supposedly rigged, if that makes a difference.)