This is one very ambitious undertaking! I have never had an open house or party this big so I hope that some other people will jump in and help here.

I would look for appetizers that you can make-ahead and freeze. I was thinking that you could make a ham, a roast beef, and a turkey (since they could be served cold) and have cheese, lettuce, tomato, mustard, mayonnaise, and finger rolls so that each person could make their own small sandwich. You would probably need more than one of each (ham, roast beef, and turkey). I was also thinking about pulled pork or beef barbeque but, honestly, I have no idea regarding amounts to tell you. For this, you could borrow every crockpot you could find but I wonder about keeping them all plugged in without blowing your homes circuit breakers or fuses. You could also have 3 or 4 (or moe) hollowed-out watermelons with fruit salad (pieces of cantalope, honeydew melon, watermelon, pineapple, strawberries, and seedless green grapes) in them. You could also make cookies and freeze them ahead of time and/or have a large sheet cake made by a bakery. I do have a cookbook called Cookery for Entertaining but the largest amounts it gives for suggestions for amounts is for 48 people. If you have vegetable trays, this book says that you can cut up vegetables 3 days ahead of time, put them in plastic bags and refrigerate them, if that helps.

For 48 people:
Appetizers
Dips, spreads and pates - 5 cups
Nuts- 3 lbs.
Potato chips-8 (6 oz.) packages
Corn chips- 8 (9 1.4 oz.) packages
Crackers- 2 lbs.
Bread rounds- 8 (8 oz.) pkgs.

Make Your Own Sundaes
Ice cream (1 large scoop per person)- 2 gals.
Fudge or Butterscotch sauce (1 oz. per serving-
48 oz.
Strawberry, pineapple or marshmallow sauce (1
1/2 oz. per serving)- 72 oz.
Whipping cream whipped (2 Tbl. per serving)-2
pints
Chopped nuts (2 tsp. per serving)- 2 cups

Tossed salad or Salad Bar
Iceburg or Romaine lettuce- 8 heads, about 8
lbs.
Boston or red leaf lettuce - 16 heads, about
12 lbs.
Cherry tomatoes - about 4 lbs.
Croutons - 5 cups
Green onions, diced - 2 lbs.
Cucumbers, sliced - 8 medium, about 6 lbs.
Radishes, sliced - 2 bunches, about 1 lb.
Mushrooms, sliced - 1 lb.
Bacon, cooked, crumbled - 4 lbs.
Hard-cooked eggs - 10
Salad dressing -
For tossed salad (1 oz. serving) - 6 cups
(48 oz.)
For salad bar (1 1/2 oz. serving) - 12 cups
(3 qts.)

Fresh fruit for platter, or watermelon basket
Watermelon - 2 large (about 20 ;bs.)
Strawberries - 6, 1-pint baskets
Pineapple - 3 medium
Cantalope - 3 medium
Honeydew or casaba melon - 3 medium
Grapes - 4 lbs.

Vegetables for relish tray or basket
Carrots - 6 lbs.
Celery - 6 lbs.
Radishes - 4 bunches (1 1/2 - 2 lbs.)
Cauliflower - 3 large heads (about 6 lbs.)
Cucumber or zucchini - 8 medium (about 6
lbs.)
Cherry tomatoes - about 4 lbs.
Mushrooms - 4 lbs.
Green beans (blanched) - 6 lbs.

Miscellaneous
Butter for spreading (1 pat per serving) -
1 lb.
Cream for coffee - 4 cups
Sugar, granulated - 1 lb.
Lemons, sliced for tea - 8
Cookies (3 per serving) - 12 doz.
After dinner mints - 1 lb.

Unfortunately, no amounts were given for meats but one recipe for a 5 to 6 fully cooked ham says it will serve 10 to 12 people - that's for an open house where appetizers, other dishes and dessert (cookies) were being served.

I know that pasta dishes are popular with most people (who aren't on the Atkins or South Beach diets) so you could make several pans of lasagne (both vegetable and meat) and freeze them ahead of time. You could serve these with tossed salad or use the salad bar idea.

I hope that this information and the few suggestions have helped in some way, Valerie. Good luck with this very special party! I wish that I could help more.