I've just started using Krita, and I've read in several places that there's some sort of a "smooth stroke" type option, but I can't figure out where it is. The basic smoothing/weighted smoothing options do nothing, so I'm guessing it's somewhere else, but I don't know where.

The basic/weighted smoothing options do make your strokes smoother to some degree. But they don't slow down your stroke like for example SAI's stabilizer does, if you were expecting that. They filter strokes without applying any delay.

Anyway, what you are probably looking for is the new stabilizer algorithm (which is similar to SAI's) that was somewhat recently added. For that you'll need a more recent version of Krita.
For Windows you can get it from here (near the bottom):
https://www.kickstarter.com/projects/kr ... sts/946167

For Ubuntu from dmitryK's PPA:
https://launchpad.net/~dimula73/+archive/ubuntu/krita

Or even building it yourself.

I have Windows, so I tried to download the Windows version, but when I click on the link that's on the kickstarter, it says 404 Not Found. Was the file taken down?

Seems the file was moved on the server, here's the new location:
http://files.kde.org/krita/windows/krit ... .79.17.msi

Okay, I installed it, but I'm not quite sure how to use the stabilizer algorithm you mentioned. I've tried looking everywhere for it, but couldn't find it. Also, in this version, when I try to edit brushes, the window for it goes off the bottom of the screen so that I can't see the options at the bottom. I can just barely click on them, but I don't really know what I'm clicking on.

Stablizer is in tool options, in the drop-down.

The higher the distance value is, the more it'll smooth.

What is your screen-resolution, btw?

That was the one place I didn't look, actually. Thanks!

My screen resolution is 1366 x 768.