What are these settings on my nikon d3100?

On the top next to the "MASP" there are four settings.self timer, continuous, and a Q and an S. What do the Q and S do?

Stop being lazy and read the instructions that came with your camera. If you don't have the instructions, download them from the Nikon website.

Where is your user manual?

M = Manual mode
A = Aperture priority mode
S = Shutter speed priority mode
P = Program which makes your fine camera nothing more than an expensive P&S camera

The self-timer should be self explanatory
Continuous is what you use if you want to machine gun your subject
S means that the auto focus is for picking a single focus point as you take a shot.
There may be a C auto-focus marking and that is so you can continually focus on your subject as it moves
Q is for quiet shutter mode.

This is All in your user manual. Look on pages 4 and 5

What happened? Did you throw it away?