Matt, unless your school ballpark is lit up like Citizen's Bank Park, I have a feeling it isn't going to be very pretty... no matter what you do. And unless somebody is sitting there with you, they aren't going to be able to give you any specific recommendations about exposure. However, I'll toss out some general suggestions:
Set your ISO as high as you can while keeping the noise tolerable/fixable. That's key.
Try to get as close to the action as you can. Long zoom settings will suck up a stop or two of light compared to wider angles.
Get onto the field (or the edges) before the game, but after the lights have begun to have some effect, and get a white balance and manual exposure setting. Once the game starts, you will probably have a lot of dark background in the shot, which will cause an auto setting to overexpose anything that is better lit. Also compare the exposure settings for in-camera black & white vs. color. I have no information on whether it is so, but perhaps the camera can shoot a bit faster if it isn't chewing on color data. (And ditto for post-processing color to BW afterwards... try different modes to see which works best.)
Try to get some good shots before sunset, so there is at least a little natural light helping out. You may have to make some adjustments to your exposure as the sun goes down and the stadium lights are all you have.
Concentrate on getting "action" shots that aren't moving... pitcher concentrating on the batter before he winds up, batter poised before the swing, etc. Don't forget the coaches sitting in the dugout looking intense. If the true action shots are too blurry for publication, at least you've got something "up close and personal" to print.
Grab a shot of the final score on the scoreboard... especially if your team wins. Another can't fail desperation shot.
Good luck... don't miss your editor's deadline... share a couple of your pix here.
