qMary,
A bit of Google searching should provide you with a wealth of information for picking the correct generator for your needs. There is a lot of information about the average electrical draw for various devices, including the temporary (surge) requirements when devices first turn on. There is also a lot of info about the advantages of various generator types, sizes and features such as electric start, auto start, 1800 rpm vs 3600 rpm, diesel vs gasoline vs natural gas, extension cords vs transfer switches, etc.
You failed to mention your budget and the importance of convenience to you. Both are extremely important in picking a system. If you have deep pockets, you can get whatever you need or desire. Otherwise, you'll have to make some trade-offs. Can you save the cost of electric start by finding a helpful neighbor?
I've got about $800 invested in a medium generator and a smaller generator. With them, I can keep my refrigerator, my freezer and an emergency small window AC ($100 or so) running in addition to a small number of convenience items. Note that I can only run one large item at a time, but those devices don't have to run continuously. You just rotate among them.
Advise - if you know that a hurricane is heading your way, turn the fridge thermostat very low - about 35 degrees. Turn your freezer thermostats as low as they will go and also fill as much space as possible with plastic containers full of water. These blocks of ice plus the low temperatures will allow the food in the fridge and freezers to survive a much longer outage. Don't forget to turn the AC as low as possible to also provide comfort for as long as possible after the outage hits.
Dorm-sized fridges are a nice second fridge around the house. If you buy one, then during an outage you can remove non- essential items from the dorm fridge (pop, beer, etc.) and load it with the critical items from your big fridge. The dorm fridge uses much less electricity and is easier to run off of a small generator.
Also, compact fluorescent light bulbs are very popular and practical for saving energy. They are particularly useful when you have to rely upon a generator because these bulbs produce the same amount of light for about one fourth the electrical consumption. These CF bulbs will reduce the load on your generator, but keep in mind that the savings in electrical consumption for a few light bulbs is somewhat trivial compared to the load of big items such as a freezer, fridge, hair dryer, toaster, microwave or window AC.
You've also got to consider how much gasoline you are going to need for a "typical" emergency and where you are going to obtain the gas during the emergency. I own 4 vehicles plus a gasoline pump, so on average I've got access to about 60 gallons of gasoline from the vehicles. Of course, I still need to drive and I'm not sure how available gasoline will be in an emergency, so I've also got 60 gallons of gasoline stored in the shed.
I'd like to hook my generators up on the natural gas supply, but there is a non-trivial cost for the conversion parts, the conversion process and the hook-up to the natural gas. If you do the installation yourself or get it done for free by a friend, then you save considerably and I'd guess that the price drops down to about $150 or so. Please note that a generator converted to natural gas puts out about 10% less electricity. Also note that most conversions are reasonably permanent and you can't just toggle back-and-forth between natural gas and gasoline.
Final advise - try to find somebody with whom you can discuss this decision. It is just too complex and difficult to have a really useful question-and-answer discussion on a newsgroup.
Good luck, Gideon