Q: how do you track a photo book you purchased through aperture?

Usually the email you got sent includes instructions for checking on the status.

Have never received email.  Could it be they have not processed order.  Do they send email at order placement or time of shipment?

You can find more information about Apple Print products on this page. There is an Order Status link on that page in the Order Status paragraph. It will require you to log into your account unless you have the order number and the email address that was used for the order.