I've figured out what most everything does, but I have a couple of questions. First, here is the picture. Not a really good one, I'm afraid, but it should do.

OK, what is the button that is half black and half white? On the black half it has OTK and what looks like an arrow, or maybe an A without the crossbar. On the white half it says BK ahd is followed by that little arrow or A symbol.
Next, why does the photocell below the lens (I assume it is a photocell, looks like one) have aperture numbers on it?
That's it. The rest is pretty much self-explanatory. I know that the film speeds on the dial that is on the green metal part closest to the lens is in GOST, not ASA. I have a conversion chart for that.
.