For the basics of this project (motor interface and control boards) you will need: USB interface board : http://www.maplin.co.uk/usb-experiment-interface-board-42857 2 computers (software WORKS with windows xp and vista, ...
These USB interface boards are great and terrible at the same time
They are very easy to use if you have loads of diodes and relays laying around at home
I havent really figured out the analouge inputs / outputs yet either
I got mine assembled just for the guarantee that it will work, but they require pretty good skills and a steady hand to assemble yourself in a kit
The board itself is plug and play with xp/vista, and the software was written by my friend dom in VB.net (2008 for client 2010 for server)
It communicates with the board using a DLL, the software is very easy to modify if you know the basics of VB.net.
I have connected my relays to the board as follows in the attatched images