Tie a little loop to start with and hook it over one of the pins on the top, go round the pins looping the wool round the pins, get it so you have two loops over each pin then take the bottom loop and hook it over the top one on the pin - do this on all four pins in turn, pull your thread which is hanging out the bottom, then wrap it round again and continue.
That probably makes no sense without the pictures, you end up with a long cord, and then you have to find something to do with it, I think I ended up sewing Alicia's into coaster
Googled it
http://www.waynesthisandthat.com/knittingnancys.html