AF/AE Settings For Action Sports on Canon 20D?

I've been photographing sports now for about a year using a 20D (see
http://www.JustPhotos.ca/galleries/sports/) but I don't feel that I'm using
the best camera settings to maximize my percentage of sharp, in-focus
shots. I'd like to hear how others set the 20D (or a camera with similar
settings) to maximize the chance of getting good action shots.

Specifically, on the 20D what setting do you use for "C.Fn 4" and "C.Fn
13"? Which AF point(s) do you select? Do you use the AF/FE Lock button
and how? These are just some sample questions that come to mind. I get
the feeling that I've not been making the best use of all my camera's
available features for shooting fast-action and I'd like to change that.

I'd love to hear the 'tricks of the trade' from someone who shots action
sports with a 20D or similar camera. TIA