Here's a great list from Naomi Gladen.
Resolve not to do all the wedding planning. Brides seem to get stuck with all the phone calls and trips to the flower shop and all of those other tasks. You don't have time for that, girl! Make sure your fiance understands that this is both of your responsibility. And don't' be afraid to delegate. Hire a wedding planner will help tremendously.
Be nice to your partner. It's almost inevitable that you two are going to bicker a little bit about all this stressful planning, but resolve to keep this to a minimum. Spend as much time as you can together doing something other than wedding planning.
Resolve to concentrate on your new marriage, not just on the wedding. This commitment you're making is much more serious than your choice of party favors. Spend some quality time talking to your fiance about your relationship and about this big change you're about to experience together.
Remember to enjoy yourself. This is a joyful occasion. Don't forget that!