I used a bipolar stepper motor in my final project. I tried both a NEMA 17 motor, which was probably a bit too powerful for my application, and a little bipolar stepper motor that came with an Arduino motor pack. For the NEMA 17 motor, I wasn't sure if my board could power it, or if it needed to be powered separately. The little stepper motor had 5 leads, which was confusing since the NEMA 17 only had 4. I eventually got the stepper motor working in Arduino IDE.