You tighten the OPPOSITE side of which direction you want the track to go, so if you want the track to move to the right, you tighten the left hand side.
On a Ski-Doo, the proper overall tension for the track is to have about 1" to 1 1/4" of gap between the slide rail and track, when you pull down on the track in the middle with about 15lb of force. I usually just hook a fish scale on one of the track clips and pull down. Get the track lined up nice and straight, tighten or loosen both sides equally (I count the bolt turns) as needed to get the correct overall tension and then tighten all your jam nuts and axle bolts and Enjoy!