Where I live in Pennsylvania, the power goes out several times a year. The longest so far was three days during a Christmas ice storm a few years ago. Not fun.
I have a portable, 5500 watt generac generator (load, but cheap) and a generator transfer switch wired into the main panel. Currently, I am configured to run the fridge, well pump (very important), oil heater, one light in the main bathroom (also very important), and several other convenience outlets. So far so good. At least I can get a shower before I go to work.
The purpose of the transfer switch is to connect the desired house circuits to the generator without feeding the power back into the local utility grid. Basically, you just power the circuits you need not the entire house. Connecting a generator to your home's electrical system by plugging it into an existing outlet (without flipping the main breaker off) feeds power back into the grid. That means the lineman 25 feet up a pole, trying to fix your power supply problem, could find a live wire where he doesn't expect one.
I know it sounds like a hassle, but if you're going to do this its worth doing right. Get a permit and get it inspected.