If we use a catering service, it's going to be our biggest expense. But I have family members and friends who range from professional chefs to really good cooks.... So we are contemplating doing it ourselves. I found the following website that seems to have some pretty good formulas for ensuring you have the right amount of food.
http://www.angelfire.com/bc/incredible/Buffetchart2.html
Anyone else have helpful hints, or experience in doing this?