1: Back up your data and keep the copy in a safe place.
2: Shut down your computer and turn off your monitor. You should also turn off any peripherals, such as printers and external drives.
3: Unplug the power cords from all devices. Surges can happen when power is restored. Unplugging from the wall will help insure the devices will be protected.
4: Unplug the network cable going to your computer, as well as your printer (networked printers only). Lightning can send voltage through these lines, possibly damaging your network cards. Although, there is grounding protection in place in all of the buildings on campus to help prevent such events, it is still a good protective measure to take.
5: If located near a window, you may want to cover your computer with a garbage bag in case water comes in. (NOTE: Be sure to unplug the power from the devices before doing so. This will insure that the computer does not over heat when power is restored.)