stepper motors are very similar to regular DC electric motors. The only real difference is they have multiple coils, while DC has only one. so to operate a stepper motor, you are to activitate these different coils in particular patterns to generate motor rotation, similar to pwm of dc motors. because of this they are usually two extra wires, usually signal wires I believe, and because of this they are harder to control, but a teensy bit more accurate.
My question to you is, is it really worth it? Time/debugging stepper motors, when a cheaper/faster dc motor driver could be made. I dont know, but when I made one I used this schematic:
Except I used either an Atmega8 or Atmega 644, I cant quite remember