I'm a first timer to Acen as well, and would like to express my appreciation to the contributors of this great thread! I went to GenCon in '02, so I kind of have a mental image to prepare me for Acen, which I'm greatly anticipating, and this thread was a very useful reminder.
Having gone to the Dear Friends concert there in Rosemont last week, I would like to suggest a couple of things not neccessarily con specific, but useful for any kind of trip like these. I saw reminders to bring food, meds, inhalers, etc. to the con, well, in the middle of winter sure enough we just missed a storm on the way back up to Wisconsin from Chicago the day we left and wouldn't have had certain supplies, so make sure whatever you need to survive bring enough for an extra couple of days without overloading yourself in case of unexpected weather or delayed flights and whatnot. One of my friends who lives in England flew out here mainly for the concert lol and got back home with just a few dollars in his pocket, so when he comes back for Acen this year he'll be loaded lol.
If anyone else is from the central Wisconsin, please let me know, as I know NO ONE here that hardly knows what anime is!! @_@ lol so once again thanks everyone for the nice reminders and suggestions!