By Position:

	Pitcher  helps to make sure the runner doesn't get to second.  His job may include backing up an errant throw, or cutting off an over-zealous runner.  It's unlikely the pitcher would be involved in a rundown.  If the ball is hit deep, he should move instead to back up 3rd.
	Catcher  prepares for an overthrow to first, and can get involved in a rundown, backing up the first base position.  If the ball is hit deep enough to left, the catcher should stay to protect the plate.
	First Base  plays the bag, making sure not to interfere with the runner.  With the catcher covering the bag the 1st baseman can move in behind a runner for a sneaky out, but that play should only be used in desperate situations, and even then only against a foolish runner.  Remember to never be that foolish runner yourself.
	Second Base covers the bag only if the SS goes out for a cutoff or is otherwise taken out of the play.
	Third Base covers third in the unlikely event the runner makes a move for it.
	Short Stop makes a quick decision to either lineup for a cutoff to second, or covers the bag.  If you do take a cutoff, be ready to fire it to 2nd if the runner thinks he's fast enough to make it.
	Left Field should always be ready to move.  Snap up the ball and throw it to your cutoff as quickly as possible, always remembering to throw it to his glove side.  If the ball is not hit too deeply, you may throw it right to the bag.  But be careful, and know your ability and the speed of the runner.
	Center Field should scramble over to help the LF, even if it looks like an easy play.  You never know when he might slip, miss the ball, or have it ricochet off of his glove.  Don't be caught watching your teammate's embarrassment when you could have helped undo it.
	Right Field comes in to back up an errant throw to second, and be ready to help everyone know where to throw it..

The Team communicates.