From a specific type of USB device, yes. From USB devices generally, no. It's rather like saying: "How do I get data from a PCI bus device". There is no general answer because PCI is a bus and the way you interact with a graphics card is vastly different than the way you interact with a USB host controller. In that respectUSB is identical to PCI.

Forget the "Serial" bit of "Universal Serial Bus" - it has no relationship with RS-232 serial which is the "serial port" protocol that you are talking about. Think of it as a Universal Bus and remember that the way you might communicate with a digital camera is rather different than the way you communicate with a keyboard or mouse.

Actually, for most USB devices the USB part is irrelevant in terms of high level control of the device. You need to access the API presented by the device driver for the specific device you want to use.