Catering help

I am looking to develope a catering menu for buisnesses and have no idea were to start.
I do not know what prices to charge and or how to package the food for delivery, or for sale…Ie 10 pizzas for what price. how many are fed per pizza. etc. any help would be greatly apreciated. thanks.

Average person eats 2.5 slices of a 14" pizza if its an office full of ladies go down to 2 slices if its a construction crew go to 3. Everything over 10 pizzas and I give a 10% discount. I find most people will call 24-48 hours ahead for the big orders (over 20 pizzas) so it will give you some time to get ready but be prepared for last minute orders. I had one for 90 pizzas phoned in late last so make sure you can handle those and yes sometimes that means going in the night before untill 2 am making dough!!