re: What to do on the day of the wedding for groom/groomsmen?

Go have a nice breakfast somewhere. Head up Magazine Street for a cigar at Mayan Import Co., or go to Don Leoncio on Canal Street THEN proceed to Aidan Gill on Magazine Street. and have your guys get a real, barbershop, hot-towel shave so you'll all look like a million bucks for the wedding.

Roll out of there and hit up one of the fine eateries on the same street for lunch.