There are 2 basic types of generators: portable and permanent. Always follow manufacturer instructions applicable to your particular generator.
In general, to use a portable generator correctly, connect the appliance you want to use to your generator via a heavy-duty extension cord rated for the size of your generator. Do not plug the generator into an electrical outlet or run it through the electrical panel of your home without a professionally installed cut-off switch, which will require a City of Springfield permit and an inspection. Doing so is very dangerous and can threaten your life and that of utility crews.
Find a dry place for your generator outside, at least 10 feet away from your home, and never near windows, doors, or vents. This is to prevent deadly carbon monoxide fumes from building up in your home. When using a generator, be sure to also use carbon monoxide detectors.
Permanent generators can provide more power than portable generators and are wired directly into your home’s electrical system by a licensed electrician. They must include a transfer switch that prevents electricity from feeding back onto utility lines, which can be lethal to line crews working on power restoration.