Here is a site with video to help.
http://www.knittingatknoon.com/provisional.html
Hope this helps.

Thank you so much. I had never heard of this before.

Mirren, I am knitting the same hat right now. I ended up not doing the provisional cast on, because I couldn't figure out how to do it. I just sewed the two ends of the band together. This was my first attempt at cables, and I love the look of the hat. I am now getting ready to finish and am switch over to the double pointed needles, which I have done before, but am not really comfortable with.

The video was great and showed me exactly how to do the provisional cast on, and I will definitely do it next time.

Yes that video was great. I tore mine out and will try it again sometime later.