rent audio equipment and speakers (unless venue already provides them), then hook up your ipod to the equipment. . .find a friend that you can trust and doesn't mind being a dj for the night. . .
Close. Don't use an iPod because of the silent delay between songs. We used a laptop so we could cross fade. And I got to sleep with a bride's maid as payment.
In addition, if you set up a play list in advance, there's really not a lot of work to be done. Just move a few songs around as you're gauging the mood.
Lastly, set up a 5-6 song chick friendly set so the guys can go outside and smoke a stogey and do shots.