Mika Sandström of Finland wrote on rec.games.bridge:
Thanks in advance, Mika
Put the right boards on the right tables, and any shares/relays/resting boards in the right place. Call moves promptly (a little ahead of time, if possible). Score quickly but carefully (sacrifice speed for accuracy if necessary). When called for rulings, always carry the book with you, and make sure that your playes can see that you are refering to it, even if you think you know the ruling. When reading out options for, say, a lead out of turn, don't just fire them off like a machine gun: Speak clearly, and glance at the players for a second after each choice to make sure they've heard you.
In more difficult situations, give everyone a chance to speak, but not all at once, and encourage brevity. Give as accurate a ruling as you can, and if the situation demands it, advise the players of their right to appeal. Keep play going: Don't let events at one table hold up a movement.
Try to keep an open mind, even when dealing with old adversaries: This time they might be right!
Finally, after you've given a ruling (and this will sound stupid, but it really does work) back away from the table smiling at everyone (not grinning like an idiot: Just a polite expression). Everyone's happy if you do this! True!
Good luck, and try and enjoy yourself as well - it sounds as though at your club being chosen as director for the year is an honour, not a chore.
The above article is the best simple description of how to be a good Director that I have ever seen.
There are, perhaps a couple of things to add. Get to the club a little earlier than seems necessary until you are experienced, and when preparing consider all the possible numbers of players you may get.
For an opening lead out of turn, exceptionally, my advice is to learn a spiel, not to read it from the Law book, because it does not work. For everything else follow Ian's advice, and read it [or appear to].
Feel free at any time to ask me for advice direct on any aspect of Tournament Direction at firstname.lastname@example.org
Here is a recommended 'spiel' for an opening lead out of turn, based on an opening spade lead, taken from Duplicate Bridge Rules Simplified [the Yellow book], which is published by Mr Bridge
When a Defender faces an opening lead out of turn, the Director should say to the Declarer: