The first step to creating your working food storage is to develop a meal plan. This shouldn't be too hard because most families eat the same meals over and over. You need to sit down with your family and create a list of meals that everyone likes to eat. The more meals you're able to write down, the better, because variety is the key to any food storage. (There are also a number of books out there that have recipes for food storage items. These might help when planning meals.) This should include meals for breakfast, lunch, and dinner. Once you have a good list of meals now it's time to start figuring out what ingredients will go into these meals that will store long term.
Most meals can be created with ingredients you can store long term. One good thing is to find commonalities between your meals; ingredients that would go with a number of your planned meals so you can store a lot of that ingredient. You can find a lot of your long term storage items at any supermarket, but some items you will need to improvise on, or purchase from a supplier. Your food storage needs to be independent of everything other than water and a heating source to cook with. Recipes that need things like cheese or milk that require refrigeration can be replaced with powdered cheese and powdered milk.
Some things such as meats can be home canned for long term storage, rather than relying on freezing them, which keeps you attached to the grid. Creating a long term food storage isn't hard, but will take some planning and work on your part. The use of a dehydrator can help you when creating your food storage. There are a lot of things you can do on your own (dehydrating and canning) rather than buying it all from suppliers which is going to be expensive. The idea is to create the storage, and not be out anymore money that you usually would when buying food.