My generator has been professionally wired in. My main concern is running my well pump. You will find that it takes many times the rated running wattage of a pump motor, to start it up. Once started, it will draw much less. I found out the hard way when I burned out a 3000 watt surge generator, trying to pump the well. The new setup is rated for 7000 watts surge, which will start the well pump no problem. If I can periodically run the well pump, I can fill water barrels and I consider a water source a critical necessity.
Since the generator is wired through a transfer switch and breaker box, the well, furnace and appliances can be separately selected, to avoid an overload on the genny. If you plan on running a well pump, find out the horsepower rating of your pump motor and how many watts it takes to spin it up. If your generator won't supply at least that much juice in a surge, you will burn it up.