It won't be in your mailbox.... I'm pretty sure that would be a felony. They will deliver to your door unless you're in some fancy high rise whatever (no clue about that?).
Typically, it will say something like 'on the truck for delivery' when they're shipping it. FedEx doesn't ship on saturdays so you're most likely going to see it Monday or Tuesday.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry