As I look at the LDS guidelines, water storage seems to me to be the most important. You can go for quite a while without food, but even one day without water is debilitating. So our first goal is going to be water.
Our first goal is WATER STORAGE.
Determine which containers you will use to store your water. You also need to decide where you are going to store your water. I wanted to separate these two items, but you can't. Which containers you choose depends a lot upon where you have space to store your water.
Some possible containers: 55-gallon barrels, 7-gallon jugs, commercial water bottles, pop bottles.
Some possible locations: In your basement or garage, under your beds, above your kitchen cabinets, in a box at the bottom of a closet.
Don't store plastic milk jugs (or the portable water containers made out of the same plastic). I know from personal experience that they will eventually leak. Also, I wouldn't store water in glass containers because they are prone to breakage in many emergency situations. Don't store water next to chemicals that might leach into the storage. Ideal location of water: in a cool, dark, accessible location. We have our 55-gallon barrels out in our garage. It's not ideal, but it works for us.
How much? Start working towards 14 gallons per person as the minimum. That amount would provide ONLY drinking water for two weeks (one gallon per day).
Need some help figuring that out?
1 person: 14 gallons
2 people: 28 gallons
3 people: 42 gallons
4 people: 56 gallons
5 people: 70 gallons
6 people: 84 gallons
7 people: 98 gallons
If you are storing 2-liter pop/soda bottles, you'll need approximately 2 bottles per gallon requirement. In other words, one person will need 28 pop/soda bottles of water.
After you get a minimum of 14 gallons per person, and if you have room to store additional water, 28 gallons per person is a better amount (one gallon a day for drinking and one gallon for cleaning). Do you have room and motivation to do even more? Great, the more water, the better.
This link gives you all the previous posts on water storage.