How do paraglider controls work?
I think the answers so far neglect the curvature of the paraglider sail. Changing the lift at the tips creates an imbalance of the side force caused by the downward pointing tips. This side force will pull the sail sideways and cause the sail-pilot combination to roll.

To illustrate my point, I shamelessly copied this picture and added vectors perpendicular to the sail surface, like this:



Now you will see why I used a photo: The tips of the sail are almost vertical so the side force caused by pulling the local trailing edge down has a sizeable lever arm with the center of gravity (which I assume to be near the pilot's head). @Ken's graphical representation hides this detail and fails to show the lever arm.

This side force will do two things:


It pulls the sail sideways so it will shift away from a position vertical over the center of gravity.
It causes the whole sail-pilot-arrangement to roll, in this case clockwise (from the perspective of the observer).


Next, the increased drag on the pulled-down side will retard this part of the sail, adding a yawing moment and yawing rotation which will now stabilize the bank angle. The whole paraglider turns. With the banked paraglider the side force component of the lift force compensates the centrifugal acceleration (rotating system of reference) rsp. creates the centripetal acceleration (fixed system of reference) which keeps the yaw rotation alive.

Also here the rolling motion is started by a lateral shift of the lift vector, but the vertical component of lift counteracts the desired rolling motion. Only the lateral force, which dominates due to the inclination of the sail, is responsible for the rolling moment.

Exiting the turn is achieved by doing the same, only in reverse.

Now for pitch control: Pulling the trailing edge down on both sides increases camber and lift, so the paraglider rises and the added drag retards the sail. This causes a pitch-up motion around the center of gravity and slows the paraglider down further. Relieving tension on the risers reduces camber, lift and drag so the sail accelerates and the whole paraglider pitches down around its center of gravity. 

Therefore, any rotation is around the center of gravity. This does not need any hypothetical pendulum movement or "pendulum effect", which does not exist and is a fallacy anyways.

Oh, and one last word for the believers in the cult of the pendulum effect: I don't care that you downvote what you don't understand. Please try and argue logically and while observing the laws of physics. This, however, will involve the clear danger that you will lose your faith. Apologies for any loss of direction in your lives. That direction was wrong, anyway.