vegetable side-dish advice

Emily - Think about how the last-minute cooking will need to work out when you are planning the vegetable side dishes. Anything that can be made ahead and served cold, go with. Go with some nice bright colors and things that everyone likes, such as corn and carrots, for starters. Cranberry sauce is a must - can you claim that the canned kind is a family tradition that you hold dear?
Otherwise, think about how much oven space will be left for re-heating made-ahead vegetable dishes, either while the turkey finishes up or while it is resting and being carved.
How much stove space is left after you leave one burner for the gravy? My in-laws heat up boil-in-bags of frozen vegetables all together in one big pot, and then slit open the bags at serving time. Do you have a microwave? They're pretty fast, but re-heating refrigerator-cold food does take some time, especially mashed potatoes.
Can you ask some of your guests to bring some of the side dishes? Have some answers in mind already in case someone asks what they can bring.
Also think about how much refrigerator space you'll need ahead of time if you make dishes ahead, what serving/heating dishes you will have free, and how much juggling you personally can manage as things go in and out of ovens and pots and so on.

Final notes: smile as much as you can, be thankful that you have this problem instead of worrying where to find food to survive, and pretend that everything is okay even if something goes slightly awry. My in-laws cheerfully claim that burnt sweet potatoes are a tradition.