I spent 25 years as a mechanic for my city. Part of my job was keeping all our emergency generators running. We had everything from small units that could be hand carried up to 1200 cubic inch diesel monsters. I know a little about the subject.
To begin with, generators are a short term solution. Generally for a few hours up to maybe a week. Two weeks at the most. Resupply of fuel will be your biggest concern. Don't waste it by running the unit when not necessary.
Determine what absolutely needs to be run. Sure its nice to have a unit big enough to run your whole house. But do you really need to? The bigger the load, the higher the fuel comsumption. BTW: you'll probably become very popular with all your friends an neighbors.
Refrigerator and freezer to begin with. Certianly don't want your food supply spoiling. But even those don't need constant power. They can stay cool for a long time by themselves. Run the unit for one hour out of every four to maintain temperature. Check them every couple of hours and adjust the schedule as needed. Anything more than that is a waste fo fuel.
If its winter, heat would be nice. This is the only circumstance I can think of where running the generator 24/7 would be necessary.
Keeping up with the news is a good idea. But depending on the nature of the outage, TV and the internet may not be working either. A simple battery powered radio works for me.
Of course you will need a few lights in the rooms you're actually using. But not every light in the house.
In short, power only what you really need. Turn the generator off when you can for as long as you can. Even under a light load, as long as that engine is running, its burning fuel. You may not know how long the outage will last.
Some thoughts about fuel options:
Natural Gas: the absolute worst choice because you have no control over it. For a simple outage it'll work fine. However, in a real disaster such as tornado, flood, earthquake, etc, trees get up rooted and buildings damaged. Gas mains rupture and the valves are closed to control fires. Your generator may not run because someone, somewhere else has cut off your fuel supply.
Propane: Fine as long as the fuel holds out, but difficult to resupply if you run out.
Diesel: a pretty good choice and resupply should be fairly easy. The drawbacks are that diesel engines are heavy and generally too large to be truely portable. The smallest diesel units I've encountered were three cylinder industrial engines and you ain't gonna just pick 'em up and move them if you need to. Also, due to their size, most diesel generators have a much higher output than the average person really needs.
If you want to power the whole house, a small stationary diesel unit would be a good choice. However the biggest and most common mistake people make with diesel generators is getting too small of a fuel tank. This thing is going to burn alot of fuel. I highly recommend a minimum tank size of 50 gallons.
Gasoline: The best all around choice for the average home owner. I recommend a portable unit in the 5000 to 8,000 Watt range with at least a 5 gallon fuel tank. Most are set up to run about 12-16 hours at 3/4 output on a full tank of gas. With this you can run the fridge, freezer, a few lights and heat if needed. That's all I need to get by on.
Another good thing is that its just a simple lawn mower engine. Most of us can fix one with just a few hand tools if need be.
Of course these are just my own thoughts and opinions. YMMV.