In your case, I would probably use the 18-55 since you will be at f/8 anyway. Shoot somewhere around 24mm. ISO 200 to 400. Then, put your SB700 at full power with whatever type of diffuser you have. Next, put the center of that light source at around 9 to 10 feet high and place your stand about 3-5 ft from your camera axis. Then, take a test shot. If it is too bright, move the light back. Too dark, consider raising the ISO or moving your light closer.
Basically, you want your light to be fairly far away from your subjects so that you won't get a lot of fall off from one row to the next.
Other things, pay attention to your background, the position of the Sun, and hats/props. I would probably try to have the sun at their back if possible with a non-distracting or complementary background.
As far as hats, generally, you will want them to wear their hat higher than they normally would wear them at. If they pull it down around their eyes, the picture won't look good.
Props can be a good thing, but only if planned well. Perhaps the front row(guys on one knee holding a bat, and the middle and back rows wearing their glove. For balance, you can have the guys on the end of the middle or back row holding a bat, also. Basically, what you don't want is people randomly holding gloves, bats, or whatever. The coaches/assistants don't generally need props.
Finally, experiment and try to have fun. Oh, another tip, let them do the silly/goofy shot first. Let them get it out of their system so they will be more willing to give you good expressions for the rest of the session.