bornshooter,thanks for the tips :-) i had a read at the manual so it recognises colour and faces it will be interesting to see how it will cope with all those santas lol i will have fun anyway no pressure not a paid shoot so i will see how it goes :-)
Here's what I do. Runners and players? Select the AF point one or preferrably two spots above the center. This way the face is at focal point and the feet are still in the frame. Active face recognition and fire away. Don't worry about going out of focus, the camera will pick it up. I'd say practice.
Some other shooters I know select multiple AF points and like you say, yes you can pick the starting AF point and let it skip around as it picks up faces. The only reason I do what I mentioned is to use the dual-cross type AF sensors and usually in the sports I shoot, only one player at a time is sufficient.
Good luck and have fun practicing! Read the manual with camera in hand and try different things.