I live in an area that each winter we get at least three major storms that knocks out power for at least three days. Over the years my family and I have developed a checklist of things that need to be done as soon as a storm is predicted. You do not want to be in the middle of a power outage and realize that you don't have any batteries for your flashlight, or worse, not have any drinking water. So I want to share my list so you don't have to make the same mistakes I have done.
Step 1: Water
One of the most important parts to being prepared is to have enough drinking water. You should store at least one gallon per person per day. You should buy the water before any storms are predicted, there are many people who wait until the last minute and the stores run out.
You can also store water by filling your bathtub before the storm hits. This water can be used as emergency drinking water, or for flushing the toilet. If it is raining out, you can collect water from your downspout. I have found the easiest way is by placing a garbage bag under the spout and using a clothespin to hold it in place. When the bag gets full, pour it into your bathtub. This water is best used for flushing the toilet, unless you purify it before drinking.
Step 2: Food
Like with water, buy food well before any storm. Buy foods that do not need refrigerated and require no cooking, or at the most, only need boiling water.
When the power goes out, consume meat and dairy items first. Also try to limit the amount of time you have the fridge doors open.
Always keep frozen jugs of water in your freezer, so you can place them into your fridge to keep everything cool.
Have a way to boil water for making food and hot drinks. A simple camp stove is all you need, but do any cooking in a well ventilated area.