Congratulations! Don't freak out over the wedding arrangements. Keep them simple and remember just to have fun. It doesn't have to be "perfect" and you shouldn't work to please anybody other than yourself! This is YOUR day, not your mother's or your future in-laws' - YOURS! Just keep that in mind and know that you won't please everybody, so don't even try. Purchase a good wedding planner guide and you'll be set.
My hubby and I consciously decided not to try and do EVERYTHING for our wedding, and we started planning way in advance, making sure to do what WE wanted...and it ended up being such a relaxing day for us and we were really able to enjoy it and not be stressed out over something that didn't go "perfectly".