To find it definitively:
1. Locate the throttle body: This is the large housing connected to the intake manifold through which air enters the engine. It's usually at the front of the engine.
2. Inspect the throttle body closely: Look for a small electrical connector plugged into a valve on the throttle body. This is the most likely candidate. It might have one or two vacuum lines connected to it as well.
3. Consult a repair manual: A Chilton's or Haynes repair manual specific to your 1996 Ford Contour Sport will have a diagram showing the exact location of the IAC valve. This is the best way to be certain.
Remember to disconnect the negative battery terminal before working on any electrical components.