generators are rated on maximum watt capacity. Basically you need to know how many watts your appliances use. Watts = amps x volts. Some appliances list all three values on the UL decals. You are correct about start up needs being greater than running needs. It's applies to your fridge, freezer and sump pumps. Anything that is not energy star compliant will eat up more watts than rated continuously. Hair dryers, Space heaters, etc. are energy hogs. Their watt rating is what the device generates, not what it requires to run. It will require more power to run because they are not 100% energy efficient.
If the generator is not an inverter type, make sure you use surge protectors for electronic devices. Honda makes very good generators, both conventional and inverter type, but you will pay a premium for their quality. If you go to
http://powerequipment.honda.com/generators/generator-power-management it lists a general amount of running and start up watts required by various household appliances. I have a 2000 watt Honda portable inverter generator and it can power my fridge/freezer, sump pump, and a few lights, one tv and cable box. If I am going to use the vest and neb, I unplug the sump pump or fridge. You just don't want to overload the generator if multiple high start up appliances try to kick on at the same time. The generator simply can't provide the required power and you risk damaging the appliance. I run heavy duty, outdoor rated, 1575 amp cords from the generator directly to the appliances and one to a power strip. Current capacity drops the longer the extension cord. You can't use a regular house hold extension cord for these appliances, that's a huge fire hazard.
I bought my generator last year during the power outage caused by Irene. I considered buying a 3000 watt inverter generator but did not want to spend $1000 more for 1000 more watts. Honda generators at Honda dealers were the only ones in stock, so I paid a premium for being unprepared. Was without power for 4 days, bought the generator, ran it for two hours and the power came back on. Go figure. You can get different brands rated for more power that cost less at Home Depot when they are in stock. I dont lose power often. Since Irene, I only lost power for 14 hrs due to Hurricane Sandy.
So if you don't want to be bothered with unplugging this to power that, you'd be safe with a 4000 watt generator. Otherwise you could get by with a
2000-3000 watt generator. As for safety, Generators must be run outdoors, away from windows. If possible they should be sheltered from the elements, but not enclosed. Hope this helps.
Ron. 39 w/CF
In NJ, cleaning up after Sandy.