The menu!  Break down how you want to work meals.  We chose to eat out as much as possible (dinners) since that is the thing that takes the most time out of your day.  We opted for easy breakfasts like pop-tarts, breakfast bars, cereal and fruit.  Lunches usually consisted of cold cuts, chips and some snacks.  Dinners were anything from Hamburgers and Hot dogs to spaghetti to chicken and beef.  We tried to offer a variety and to eat dinner out every other day.

Your menu will vary on a few things:
Your tastes, Simply what your group likes to eat.
Shopping opportunities, When you get into places like Yellowstone your opportunities to buy food become limited so you need to plan very carefully as to what you have & what food can last in coolers.  We went with more perishable items on the first day after the shopping and worked our way down to items like spaghetti.
How much you want to cook -  how much time to you want to spend cooking and cleaning up?   It does take a lot of time and if you are wanting to experience the sights of the trip you could easily be cleaning up dinner stuff at 10 to 11 at night.
Dietary concerns: Do you have someone with food allergies?  Do you have vegetarians?  Someone with diabetes? Make sure to take these things into consideration. 
            Your activities:  Will you be doing backpacking? Where it needs to be light weight or will all gear be based out of a vehicle?

Trying to offer a balanced meal can be difficult on a large scale but is not impossible, see our menu (in the resources section) for what we did.
We did buy snacks for the group including crackers, cookies, fruit cups, etc…  But you don’t have to offer this we were just trying to keep gas station stops as quick as possible.

Your storage space would be a factor, do you have room to store a lot of food?  With our set up in the gear truck we had lots of space and ended up having extra food left over.

Predicting your food consumption is an art more than a science.  How much do people eat?  Will they be hungry more? Or Less? Sometimes the people you don’t expect to eat a lot keep coming up for more and others that you would think would eat a lot don’t.  Take your best guess based on the serving size and try to duplicate items.  We split the menu in half for time repeating similar meals so if we had some unused from the first part of the trip we could use them up at the 2nd meal.

Here is our sample menu: Sample Menu

Here is our sample supply lists: Sample Food & Supply Lists

Eating out:
If you are planning to eat out do your research to find restraints that can handle your group and see if you need advance reservations (can be needed if it is a large group).  Plus cost will be a factor, don’t forget to factor tips (even for some buffet restaurants) into the costs.  A possible solution for eating out is going to a place that has several different fast food restaurants in close vicinity, one group goes to McDonalds, one group to Dairy Queen, one to Wendy’s just getting them back together is the only trick.

Will you be going to a place where wildlife is a concern?
Most every place has some concern with wildlife most are nuisance but some can be life threatening like bears and wolves.  Or dealing with large animals like elk and buffalo.

Since we were in an area with predatory animals, we adopted a strict policy on food and gear:
Food – all food was stored in vans or gear truck after cooking all kitchen items were packed back into the gear truck.  People could store personal food in the truck with their name on it.  Under no circumstances was food to be in the tent.

Also concern with was clothes with food odors on it, they should have separate clothing for sleeping and keep the rest in the truck.

All personal gear (duffels) was to be kept in the truck, people could get out what they need and put the gear back when done.  Personal hygiene items like toothpaste can attract animals.

Back country participants needed to hang their gear from trees.