If your UK school lights are anything like the normal school lighting in the U.S., they are not very bright. This makes shooting under the lights a tough situation, especially if you don't have a fast lens and/or a camera which will provide decent imagery at high ISO.
I would boost your ISO up as high as your camera will provide acceptable imagery. IMO a sharper image with some noise is more appealing than a noise free image which is blurry. Many post processing programs can reduce or get rid of noise. I would not hesitate to shoot at ISO 800 or even 1600 using my 40D camera.
Shoot wide open using aperture priority so you can keep the shutter speed up there. Hopefully your lens is fairly fast - such as f/2.8 or faster. However, you will just have to make do with the lens you have.
IS, if your camera/lens is so equipped, will not stop the motion of your subjects but should stabilize the background somewhat. Sometimes images wherein the foreground and background is sharp and the players show some motion blur are not all that unusable. They give the impression of speed and motion. BTW: using a monopod will help generally stabilize your shots.
I would choose the center focus point and exposure that is weighted toward the center.
Shoot at the peak of action; such as a player jumping - catch that player at the top of the jump when there is an almost imperceptible pause in action from going up to coming down. There is really a split second wherein the subject is hardly moving at all.
Players coming towards you or going away from you can be stopped with a slower shutter speed than players moving across your frame.
Shoot in RAW so color balance will not be a problem and so you have the advantage of the post processing controls allowed by RAW captures.
tomorrow I am going to be taken photos at a rugby match the problem is it will be between 3.30 and 5.00 when it will start to get dark I know there is flood lights at the school and they will be using them, my problem is I have never taken sports shots under floodlights and was wondering if anyone could give me any advice as how to tackle this situation or will the shots not be affected by the floodlights
