If I adjust these knobs clockwise or counter-clockwise, what exactly will they do?

Do they just pull the brake shoes closer or farther from the rim?

Can't you just turn them and find out?...I believe counte-clockwise will pull them closer...

I did turn them and I didnt notice a difference. Thats why I asked.

Those are your barrel adjusters.

What they do, and this may seem confusing, but: By turning them counter clockwise, (out) they lengthen the cable housing. By doing this, since the cable is fixed, lengthening the housing effectively shortens the cable and pulls the calipers closer together. As a result the brakes tighten.

Now, the black nut in between your barrel adjuster and the lever housing is your lock nut. Turn this clockwise while holding the barrel adjuster all the way in to where it is snug against the lever housing. This will lock the barrel adjuster and keep it from turning.

Now, if you want to decrease the distance that the lever is from the handlebar, you can adjust the screw sticking out. That pushes the lever closer in.

L8R

Not confusing at all, makes complete sense. I knew thats what they did, just wanted to be sure.