I recently purchased a Honda inverter generator to power one television/DVR and two computers/internet service during a power outage. The three items (all connected to their own UPSes) are located in different areas of the house. To make connecting them to the generator convenient, I ran 12/2 NM and hardwired outlets to each location, connected to an inlet in the garage. These three outlets are not connected to the house's electrical service in any way. When the power goes out, I must unplug the UPS from the wall outlet and into the generator powered outlet.
The one thing I am unsure of is if I need to provide any additional grounding for this setup, or if the grounding provided by the generator itself is sufficient? If it makes a difference, the television is connected to a roof mounted antenna which has its own ground rod, and the internet is provided through the cable company's connection, which is grounded to the house's copper plumbing.