I found this link, but it's gibberish to me. What do each of the pins do?
Here's what I figured out. Let me know if it's correct:
1) 5V into pin 16 powers the H-bridge, but not the motor.
2) H-bridge is inactive until pin 1 receives a HIGH from the Arduino.
3) If pin 1 and pin 2 are HIGH, the 9V (sourced from pin 8) will supply power to pin 3.
4) If pin 1 and pin 7 are HIGH, the 9V (sourced from pin 8) will supply power to pin 6.
5) Pin 4 and 5 are ground.