Quote from mgookin:
A male to male plug invites the following hazards:
1. Fire or Death by electrocution from someone pulling it out of a plug and knowing that all their life the male end of a plug is not hot.
2. Fire or Death by electrocution from the plug falling out, being knocked out, or vibrating out (think running generator at one end) of the receptacle it's in.
Plugging into "a couple receptacles" invites fire or explosion not to mention ruining your generator and a chuck of your building too. You can't connect two outputs from a generator on the same line/ neutral combination. The fact that you are in two different receptacles or on two different circuits does not give you any better than a 50% chance of being right or wrong.
Most people should not work in their main distribution panel (called an MDP). Is has much more power in it than you want to do the tango with. Have an electrician install you a safe transfer switch.
If you are brave enough to work in your panel and there is a local disaster resulting in several days without power, a safe (safer?) thing you can do is the following:
Shut off the main and all of the breakers in your main distribution panel (called MDP in the industry). Dedicate a two-pole breaker to the generator. You can do this by installing a new two-pole breaker or you can remove the conductors from something you're not going to use (the clothes dryer maybe). Build a properly sized cord set with a male plug on one end and stripped wires on the other end. Run your cord set from the 220V (USA) output of the generator to the panel and connect to the neutral bar and each of the lugs on the two-pole breaker. Start the generator. Switch the dedicated two-pole breaker on. Turn on the breaker for one lighting circuit to see it work. Now I'm going to show my age. You need to do a "Green Acres" and add up the watts consumed by each of the electrical devices you want to use. You can run the fridge at night. You can maybe run your water heater 20 minutes (avg time to heat a tank of water) or even your A/C for a little while (heat if you're cold). But you can't do all of that concurrently. When power is restored locally, shut off the generator. Switch all breakers off. Remove your cord set. Put the cover back on the MDP. Switch the main on. Turn on one lighting circuit to test it. Turn on the rest of your breakers. Have a toast to power coming back on and be sure to thank those utility workers when you see them out on the street.
Worked just great during Charlie, Francis, Ivan, Gene, Katrina, Rita & Wilma for me. Hope it works for you.
Don't kill yourself with Carbon Monoxide like I've seen happen too many times. If that generator is not 100% outside of the building (a garage is not outside of a building) then it should never be run for more than 1 min. You don't want to hear it anyways. Buy an extra long length of cord and put your generator over near the neighbor you don't like.
Home Depot can help you size your cord. Don't be a cheapskate or that too will start a fire and ruin your glory.