The best advice I was given with my first jump is to relax. For some reason I wasn't nervous at all when I did jump [not just acting tough... i just wasn't nervous], but that seemed to make all the difference. After your exit count, take a deep breath and just keep going with it. You'll have more fun, be more stable and have more freefall time without duties if you DON'T rush. Rushing just makes you go unstable and the instructors have to fight to stay attached to you. Calm, deliberate movements seem to do the trick.
Don't forget to have fun. About 15 seconds into the jump you'll go "holy crap, I just jumped out of a plane. This is incredible" and the rest is gold. I really don't know what I'm talking about.