What does the ATC instruction "Make left traffic, runway 19L" mean? I'm playing Prepar3D and when coming in for a landing I'm usually told something like Make left traffic, runway 19L. I'm not sure how to interpret this because I'm not a pilot.
Should I go to the left of 19L for my downwind leg so the runway is to my right, or should I go to the right, with the runway on my left?
Also with parallel runways should I go to the left of 19L exactly or is it the left of 1R? I'm very confused!
'Left' or 'right' traffic means that when you are flying the traffic pattern, all turns are to that direction.

The wikipedia article on traffic patterns isn't bad, and has some decent graphics, including this one from the FAA's Handbook of Aeronautical Knowledge:



The top pattern is left traffic, while the bottom pattern is right traffic.