What do I need to do to play WWP online with a pc?

Obviously, I have the cd rom and high speed connection!

Thanks

You need the patch (http://wwp.team17.com/main.html?page=comm&area=_down_patc) and also make sure that you have the correct ports (http://forum.team17.co.uk/showthread.php?t=7171#7.4) open in your firewall or forwarded from your router.
(I'm not sure if all of them are necessary.)