Cash registers or adding machines with tax if you have to do taxes, people that can add, people to assist kids looking for particular items, a seperate table set up for people that want to order books that you do not have available, bags for sold items ( scholastic may provide these) cash for change these items are a must.
Have a meeting of your volunteers at least 30 minutes prior to the book sale to go over items, cashier register use, check acceptance/credit card policies.. these take a little time to explain to people.
Our schools ALWAYS have an ice cream social during the book faire it is a nice social gathering and a nice fundraiser. Do not take on the responsiblity of both things.. The social will need its own leader.
Just thought of these things.. Joan