Erin - you have not said what you nornally drink and whether or not you are used to drinking for any length of time. I would say drink something with a lot of mixer in it. Remember to pace yourself, don't mix your drinks and have a lovely time :o)
Are you a neat spirits/ wine/ cocktail person? Have you have much alcohol before? if not, I'd go for something sweeter than medium/dry wine, possibly a cocktail with sweet fruit juices in it, any suggestions? Taquila sunrises are nice.
Actually, best bit of advice about drinking I've ever followed is "stay one drink behind" - by which I mean, make sure everyone else has one more drink than you. It is the best way to avoid looking silly on Facebook in the morning.