If plugging the generator into a wall socket, I would suggest getting a proper cable. Standard leads are only 0.5-1mm thick. Standard house-wire is 2.5mm so getting the proper thickness (although, quite a bit more expensive) will prevent the cable from heating up or burning out.
It is better to have a switch installed though. Then both plugs from the generator are connected to the house, power supply is more stable and you simply flip a switch to switch between generator and municipal power. That switch shouldn't be that expensive, although can't remember what I paid back in the day. Getting something that starts the generator automatically when the power goes off... now that's expensive.
The only thing with these 5.5kva generators that you get from Game, Builders Warehouse, etc. is that the power isn't always very stable. My PC is connected to a UPS and that is connected to the power and a lot of times when the power went out, when running off the generator, the UPS would keep beeping as the power wasn't stable enough to keep it charged. Anyway, used that setup on the farm back in Nelspruit.
Now here in the city, I have a small Inverter Generator from Ryobi which provides enough power for my computer (with 3x 32" LED TVs), router, a energy saver light and my whole TV / DSTV / Home theatre system. The big difference is though that it provides very stable power for electronics.