Like water, food (or the lack of it), will be a very big deal in a disaster or situation that results in an interruption of services that lasts longer than 4 days. Unlike water, which is somewhat available (in most areas of the country) and easily treatable, food is not easy to come by. For the most part food must already be on hand, and stored correctly, to be of any value under bad circumstances.
The Golden Rule of food storage: "Store Extra of What You Already Use". We eat a good bit of rice, potatoes, and pastas. So buying a 50lb bag of rice for $19, 10lbs of dehydrated potatoes for $10, and 18lbs of pasta for $15 wasn't a huge deal. Those are the foundations for many recipes, they're hearty, inexpensive, easy to make, and everyone in my family will eat them. Having things on hand that your family already likes will make a unusual circumstances much less stressful for everyone involved. If you think your family are finicky eaters now....... imagine trying to get them to eat in the dark, while they're wet, cold, scared, and tired.
The Golden Rule can be implemented simply enough by buying one or two extra packages of what you're ALREADY buying. Buy it on sale, use coupons and discount cards, and store it away from your normal food storage. You will be surprised how fast it will accumulate. Once you have enough on hand to feed your family for a month, begin to rotate your extra food (called "preps") into your normal food storage as you use it. When you go grocery shopping simply restock your preps with what you pulled out plus one extra package, per item, of what you had on your shopping list.
We store a lot of canned goods, because we have a wide variety of tastes. With canned goods you can get a wide variety of foods including fruits, in stackable, easily storable containers, with fairly long shelf lives, that aren't very expensive. They're easy to rotate, easy to prepare, and it's easy to identify what's in them. I buy mine at Sam's Club or Costco, so they come prepackaged by the dozen. The boxes open on the end so it's easy to carry the boxes into the house, open them and stack the cans.
Store lots of dry goods ready to prepare. For example Easy Mac, Ramen Noodles, granola bars, nuts, etc. These are comfort foods, and they will comfort you in times of stress. They'll give you an energy boost when you need it most, and won't require alot of effort to prepare. I buy these things in bulk at Sam's Club so they're cheaper, and store easily. Some of the self lives can be shorter than you might think, so keep an eye on the rotation andf you'll be fine.
I store some canned meats as well, but not a large variety of them. I store salmon, tuna, chicken, and DAK Hams. At one point I stored Vienna Susages (lots of them), my kids and dog liked them at first but quickly got tired of the taste. I never liked them because they smell funny and have a weird texture. Another mistake I made was buying little tins of fish like sardines, and herring steaks. It looked like the perfect food prep, they stacked really easily and contained decent amounts of protein. They were cheap enough at less than a dollar each, and had a really long shelf life. What could go wrong....right?
Lots. They were packed in oil, which extended the shelf life by about 2 years, but made them almost intolerable. They smelled worse than they tasted. My cat wouldn't even eat them. That was my lesson on following the Golden Rule. If you don't eat it now, don't buy it for later. Of course I'd eat it if I were starving.....really starving, and had lost all sense of taste and smell. Good luck getting three kids to eat them.
We also store quite a few beans. They're high in protein, and add substance to just about any meal. Beans and rice are fundamental staples in most 2nd and 3rd world countries. We store red kidney beans, black beans, pintos, and especially lentils. Soaking them over night greatly reduces their cooking time, but doesn't take much more water than just cooking alone.
When you begin the rotation stage, that's when you begin to pick up extra items like salt, pepper, spices, oils (i store olive, coconut, and peanut oil), honey, bouillon cubes, condiments, etc. The spices and cubes you'll want because they can make bland, repetitive meals more tasty and tolerable. Oils you need for fat content, and they have a very long storage life. Honey you want because it is sweet and will store indefinitely.....literally indefinitely.
A few other odd and ends I store with food:
Toilet Paper....what goes in must come out. I'm not wiping with full sardine cans.
Dental Floss, tooth brushes, tooth paste. Dental hygeine is critical.
Liquid Soap. For obvious reasons, can also be used to wash dishes and clothes.
Those are some things I store. We don't have a lot of storage room to spare, so I have to get the most out of the space I use. Aside from the boxes containing a full 12 items of canned goods, I remove everything from the bulk boxes. Once I open the bulk canned goods, I remove them all, stack them on the shelves, and discard the box. The boxes usually contain insect eggs, which will hatch inside your house and cause you lots of problems. I either stack smaller items individually or seal them in gallon sized zip lock bags. I like the bag option because you can still see what's inside.
These are some things that have worked for me over the years. It's a trial and error process for me as it is for most. If you have any tips or tricks please share.