I hate to admit it, but I like the Martha Stewart method. (ooo, now nobody will believe me when I say I hate housekeeping! lol)
Take out the giblets (which I have forgotten to do in the past), rub it with butter, fill the cavity with peeled onions, cut if you have to but you don't need to chop it up, add a few stalks of celery and some garlic cloves, at pop it in the oven. Best is like 275F for 6 hours or so (my mom used to set an alarm and get up to put the turkey in) but you can set the temp and time according to any cookbook you like. Don't forget to baste, that keeps the skin from drying out. I usually bake it uncovered and add foil later to prevent burning.
Oh, and this is good with chicken too: If you don't have a rack to lift it out of the fat, peel a few onions and slice them thickly, then lay the slices to cover the bottom of the pan. The bird won't stick, it's a nice flavor (I think turkey is bland), and you can add the onions to the gravy or serve them as a garnish.
But the most important thing is to relax and have fun with your guests!