Be Prepared to Make Change
On the day before the sale, go to the bank to get plenty of smaller bills and some coins so that you'll be prepared to make change. Figure out how many people will actually be helping you sell items. That will help you decide how much money you'll need for change making. Stop by the local hardware store and pick up a few free aprons. Set up a bank of change for each of your assistants accompanied by an apron, some extra price tags, a black marker, some masking tape and a small calculator. You'll also want to have some shopping bags, a few empty boxes, and some newspapers and maybe even some twine on hand for packing up purchases.