We store up to a one year supply of food for our family of five, plus water and a water purification system. Our staples are rice, oats, wheat and pinto beans. All of it is vegan, as we have been vegan for decades but only recently 30BaD. We also store all types of freeze-dried and dehydrated vegetables and fruits, and are currently working on expanding that part of our storage. Just added two cases of dehydrated bananas! Freeze-dried fruits and veggies are much nicer, but also a lot more expensive.
The majority of our storage is sealed in #10 cans with oxygen absorbers and can last up to 30 years. The suggestions above are all good ones for short to medium-term storage. We store things like that as well. The problem is that as long as we have fresh fruit and vegetables, that's what we're going to eat. With our long-term storage we don't have to worry about rotating or using things before they go bad. The Emergency Essentials catalog is a good place to get started.
While we are prepared for a SHTF situation, it's not our primary concern. We do have the means of defending our home very well, but see it as an outside chance that we'd ever have to use it. We mostly plan for loss of income, whether that be just our own or a wider economic collapse. We also like the option, and have used it, of being voluntarily unemployed for extended periods of time. It's nice not having to ever be worried about eating during those times. I have also lived through multiple hurricanes and ice storms, have been without power or access to the outside world for weeks at a time. Speaking of which, we can also cook and heat our home with stored propane, without the need for electricity.
We have had this discussion on here before. Expect a lot of "live for today" rhetoric and "you can't prepare for everything" so do nothing at all! Oh well, to each their own. I have life insurance, auto insurance, health insurance...this is food insurance!