I turned the power to the printer off in ...

Disconnect the "data" cable between the printer and your computer.
Turn the printer on.
If the light still flashes, you have a "paper jam".
If you cannot "clear" it yourself, take the printer to a qualified technician, for servicing.

On your computer:
Click Start
Click Control Panel
Click Printers
Double-click the icon for your printer.
Click on the "suspended" (or "active") print-job, to "select" it.
Right-mouse-click on the print-job, and choose "cancel".