As you have by now set your own magento store and you see that the order number a customer gets after purchasing starts from 100000001. But as its your new store and you don’t want your store to look like an amateur to others, you thought of changing the value of the order/shipment/invoice/credit memo number. But as you might have found out that there is no option in magento to change the value of this. Also it occurred to you that you want to modify in a way that it has a prefix related to your store name. e.g. Your store name is BestBooks.com, so you want that your order number looks like BB10023123. It looks definitely better than the default.