Rookie

[jTheUmp]

You've got a solid foundation of officiating experience, so I'll concentrate on what's different from the sports you mentioned.

1) Unlike basketball (and, I assume, lacrosse)... you don't want to have the whistle in your mouth all the time when the ball is live... there's (almost) never a situation where you're going to need to stop a play in progress. Spit it out at the snap, and put it back in when you need to blow it to signal the ball dead.

2) There's no such thing as a late flag. (That's not entirely true, of course, but since live-ball fouls don't get enforced until after the play ends anyway, you can throw a flag 2-3 seconds after a foul occurs without any concern. In fact, in some situations it's better to wait those 2-3 seconds to let players clear out before your flag comes flying in).