The “Internet Umbrella Rack” project in chapter 10 (Python and the Internet) of the excellent book “Getting Started with Raspberry Pi” by Matt Richardson and Shawn Wallace
Interesting components of the build are:
A hand built circuit board with 1) a header for the GPIO ribbon cable from the pi, 2) a socket for the 18 pin Darlington driver, 3) a header for the unipolar stepper motor connector, 4) two pairs of terminals tied to input pins with pulldown resistors to ground for the momentary switches serving as calibration buttons