Start out as organized as possible
There is going to come a point when cooking a complicated dinner where things dissolve into some level of chaos. But there are ways to minimize it. A few days ahead, make a note of how long each dish takes to cook (and what can be made or started a day or two ahead) and make yourself a schedule of when what goes in the oven or on the stove so that everything is done at the same time. You'll be glad you did.
Another tip I got from my mother is to get all serving plates, dishes and utensils out ahead of time and put a Post-it in each one reminding you which dish goes in there. This is helpful when calling to a friend, "Can you put the potatoes in the bowl?" while your hands are too full to show her which bowl.
Have all your recipes handy, it can suck and get messy if you're running from cookbook to iPad checking the next step on various dishes. One solution is to print or write out recipes and tape them up in your kitchen for easy access.
Finally, take a tip from professional chefs and set up your mise en place before you begin cooking. A French term which translates to "everything in its place," this means going through your ingredient lists and making sure everything is out, organized and ready to go. Sometimes an ingredient itself requires a certain amount of prep work — potatoes have to be peeled and quartered for instance, and you don't want to discover this while the water is already boiling.
Know when to buy premade
Making your own cranberry sauce (especially if your group enjoys whole berry sauce) is pretty easy. But if adding one more item to your to-do list (or stove) seems overwhelming, a lot of grocery stores have a "homemade looking" version in the prepared foods section so you can avoid the tell-tale ringed circular cranberry from a can. However, cranberry sauce from a can is a MUST HAVE for some people. Cater to your guests' preferences.
An appetizer or pre-chopped lettuce and veggies for a salad are other great items to buy already prepared. There's a ton of delish frozen apps out there and you don't need anything extra to worry about after your guests have arrived and you're still cooking. But even some of these have some level of preparation to them — make sure to pick something that goes straight from baking sheet to platter.
Dinner rolls. Frozen dinner rolls are another thing some people have a fond attachment too, or for a more upscale feast, rolls from a local bakery will be a treat.
One final tip: don't be afraid to ask each guest to bring something! Or if you really love your best friend's pie, ask her to make it for the meal. You don't have to do everything yourself and lots of people like to contribute, even if it's a bottle of wine.