I'm not sure, but I got the canaKit for arduino (sparkfun inventor's kit) and am right now using the online manual for the motors on page 67 of the manual:
One problem is I'm missing my diode (for right now I can't find it).
Without the diode, the gear on my motor moves a drop, but it I think is too much torque to turn the bigger gear which turns the propeller.
Update: I connected the + and - pins from my 7.4V battery to the breadboard circuit. Pin #6 was connected to 330 Ohm resistor to the middle pin of the transistor. The 7.4 V were connected to the motor, and the ground of the motor was connected to the collector. The emitter was connected to ground of the battery. When I turned it on, the motor turned fast. I'm worried something will burn out if I apply to many amps or something.