
All switches of this sort have the common pin in the middle. Look at the three lugs closest to you: When the toggle switch is thrown to one side the common lugs in the middle makes connection to the opposite lug. Another way to say it is that if you throw the switch to the right then the center and left lugs are in contact. When you throw the toggle to the left side then the center and right lugs are connected. Since this is a Center Off - when in the center position neither of the two side lugs are connected to the common (center) lug. ON THE OTHER SIDE are three more lugs. They work the exact same way as the three near lugs.
What you would do on one side is connect the two lugs (left and right) together and to power. The center lug goes to your right side lights (right in reference to my diagram). (Also see the diagram shows wires connecting the two lugs)
You would connect the other side, one center lug and one right lug (you'd throw the switch left to activate) would make contact and the center lug would be wired directly to your left lights while the right lug would be connected to power.
Give me some time and I'll find a picture I can modify for you.