Some thoughts:

1. A case of baby wipes. Sometimes showering isn't an option but these will help keep you clean.

2. Headlamps for everyone in the household over the age of four.

3. Entertainment such as dice, boardgames, puzzles, cards, dominos, etc...

4. Blankets. Snuggling up under one feels great, plus you can hang them to seal off areas to minimize wasted heat.

5. Several small radios placed in different rooms.

6. Tom Brown, Jr's book on urban survival

7. Snow shovels and a safety harness for clearing off your roof.

8. CO detectors and fire extinguishers.

9. A metal bucket in which you can place fire-heated rocks to use as an indoor heat source.

-Blast

Blast - http://www.amazon.com/Browns-Guide-Suburban-Survival-Field/dp/0425091724 ?

How much water pressure is required to operate your on-demand hot water heater? I know mine will not operate with low pressure. My unit has no pilot, but two D batteries that work the ignition -- but that's signaled by a flow valve.

I`ll check the manual... that is a good question. I better make sure my minimum/cut-in pressure is high enough

beer.

When I was in a similar scenario, I chose all electric, due to the inability to guarantee LP/Propane refills.

So I switched out my water heater and floor heater for electric models and ran the generator as needed. It also managed my water pump for the well. But the hot tub turned green, so the beer is a good idea, too.

beer good

Have you considered how you will light your home when the generator is not running? presumably you wont run it 24/7 due to noise and fuel consumption.

Consider putting one lighting circuit on a UPS, use only low energy lamps on this circuit, and ensure that each room has one light on this circuit.
This has two advantages, firstly light is available instantly when the grid power fails, or the generator stops unexpectedly.
Secondly limited lighting is available when the generator is shut down to save fuel.

Candles and oil lamps should be kept in addition, but are less convienient than electric light.

Another option is a 12 volt lighting system to supply essiential lighting from a 12 volt battery bank, this being charged from line or generator power when available.

Keep a few chemical lightsticks on hand as well, these are the safest form of light for handling gasoline and other flammables in the dark.

And dont forget a high power halogen spotlight, useful for inspecting external storm damage, and looking for lost children or pets.

Remember, beer has food value, but food does not have beer value!