I bought all my electronics and steppers from Roy at DIYCNC and would highly recommend him.

I knew nothing about stepper motors, drivers etc but within 1 hour after getting the parts I had them wired up on the bench and running, it really is that easy.

Download a few manuals from the DIYCNC website and have a read, may give you a better understanding.

His new system4 board looks nice.... http://www.diycnc.co.uk/SYS4.pdf