Nick: I assume you're asking about the switch machine wiring, not the track. I'll also assume you have a Snap-Switch type and a little electrical switch that you slide and then push.
There are 3 screws on the switch machine. One is a "common" and goes to one of the AC terminals on your power pack. You can connect all the commons together to a single wire. There is also a common screw on the electrical switch. This gets connected to the other AC terminal. There are two more screws on each unit; these get connected together by two wires. Then you try the controller. If the switch goes the wrong way, reverse the last two wires.