> Jackie, you are, alas, in a difficult situation given the poor > light and the fast action requiring a high shutter speed (to avoid > blur due to the motion).
So, set your ISO to 800 or higher (the higher the number, the more light sensitive the chip is, but the "price you pay" is higher levels of noise (which looks like grain in film).
You should use the fastest aperture (the lowest f-stop number) your lens offers. This may be an issue if you are using the "kit lens" that came with the camera - if you can get a lens that goes down to f1.4 or 1.8 or at least 2.8 you'll be better off. Set the camera to Aperture preferred mode, so it will select the shutter speed based on the aperture (which as I said, you should set to the fastest possible).
Not sure if sports mode will do anything special - other than put the camera into motor-drive mode (so you can take a quick sequence of shots).
Flash is probably a bad idea for two reasons: first, it will only be useful for a limited range and second, it can prove distracting to the players.
Good luck - I hope this at least helps.