Okay, I'm confused as hell. How exactly do I download all these maps?

There are two ways of going about it:

1) Play on servers with custom maps and you should download them automatically. There's also a bug that'll boot you from the server if you either don't have it or have the wrong version, in which case you can just rejoin and they'll be downloaded.

2) Most custom maps are released on these forums under the New Maps section. Download them, unzip if necessary, and place the .pms file in your "Maps" folder. It may also come with custom scenery and textures...just stick those in the appropriate folders, too (scenery-gfx and textures).

Thanks for the help, but I'm still unable to get everything to work...

What are you having trouble with, exactly?

Well, I was trying to dowload some of DeMonic's maps, and I couldn't get them to work. I think I may be able to now, though.

Just extract the .zip files to your Soldat folder, and it'll arrange itself :) If you only downloaded a PMS file, put it into Soldat/Maps. If the problem is that the downloader opens it as a text file, then do "Right Click->Save as" instead of simply clicking.