To my northern friends preparing for hurricane Irene, some advice from one who's seen a few hurricanes:
Basically what all this boils down to is "Be prepared to be without electricity for a long time" If your area doesn't get anything worse than tropical storm force winds (i.e. you are on the edge of the storm) then you probably won't be out of power for more than a few days to a week and you might even get power back the same day, but if you get even category 1 hurricane force winds and your town has above-ground power lines, you could easily be without power for more than week. Another danger is if there's flooding, then flood waters can contaminate the municipal water supplies. That probably won't happen, but it's a possibility you should be prepared for.
What to buy before the storm: Water (the super-cheap gallon jugs), non-perishable food, Gasoline (gas station pumps don't work without electricity so fill up any cars before the storm), Cash (ATMs also don't work without electricity), Toilet paper, Fresh batteries for flashlights, Chocolate (because who doesn't love chocolate, and you need something to occupy you during the storm)
1-2 days before the storm: Try to use up perishable foods in your fridge/freezer. For example, if you have lots of eggs (which are perishable), bake a cake (which is less perishable), etc. Make sure you have the items listed above. If you have a battery or hand-crank radio, get it out and see if it still works. Figure out what's the safest room in the house in case of a tornado.
The day before the storm:
move inside everything that you have outside that's not bolted to the ground or super heavy, e.g. potted plants, lawn furniture, bird feeders, etc. Move any cars (which should now have full gas tanks) into a covered area if possible, if not possible hope for the best.
Fill plastic containers with water and put as many as you can fit in your freezer. This should keep the freezer cold for at least 2 days without electricity, and in the rare event that the water supply is corrupted you can drink them.
Another thing people sometimes do to ensure a supply of clean water is to fill up their bathtubs right before the storm and stop the drain. This is if you are expecting to get hit really hard by the storm, or if you know your town is prone to flooding.
If you have really large picture windows, or other vulnerable points in your house, you might consider taping them or putting some plywood up, but that's really mostly if you are expecting hurricane force winds.
If you have a landline, and an old corded phone (NOT cordless handset), you might want to make sure it's plugged in and working. Normally landlines still work even when power is out, but phones with wireless handsets may not work without electricity. If you get a storm of any decent strength, cell phones will not work at all so don't plan on relying on them.
During the storm: Don't play in the storm (too much :P), definitely don't climb trees even though it's really fun. Listen to the radio for updates on conditions in your area like tornado sightings, flooding etc. If you go to bed while power is out, be sure to turn off the lights so that they don't wake you up if power suddenly comes back on.
Getting Forcasts and Information
Useful websites for tracking the storm: www.nch.noaa.gov www.crownweather.com
Particularly useful on crown weather is the "Storm Wind Swath" maps.
BE CAREFUL WHEN CHECKING FORCASTS FOR YOUR AREA ONLINE. Many online weather forcasting services will give you what would be your forcast if there were no hurricane. www.wunderground.com will give excellent area-specific hurricane condition forcasts, but normally not until roughly the day before the storm (before then they'll just give you the forcast without hurricane). The National Weather Service also gives good hurricane condition forcasts Their website is www.weather.gov (NOT www.weather.com, which is the Weather Channel, whose forcasts even in normal conditions I find to be wildly innacurate)