I started playing with stepper motor using the 5.25" floppy disk drive motors as they are literally FREE (if you can find them
) Most of them are unipolar but they are some bipolar as well.
Simplest circuit, IMHO, is to use the ULN2803 as driver connected direct to PC parallel port and driven by a 5V supply (unipolar motor off course).
Check out these sites for additional ideas:
http://www.doc.ic.ac.uk/~ih/doc/stepper/ http://www.hut.fi/Misc/Electronics/c...skstepper.html
Have fun.