Beans are an inexpensive way to add protein to your diet. Buying beans in bulk will yield you an even better price per pound (see the Grains page for bulk sources. Also, Sam's Club and Costco carry pinto beans in bulk. Many other places sell other types of beans in bulk as well). If you buy beans at the grocery store, they run around $1.25 a pound. In bulk, they are .50 to .64 a pound. Since beans double in weight when cooked, this means that you are paying around .30 a pound for cooked beans when you buy them in bulk. That's a lot cheaper than buying canned beans!
Just because you're living on a rice and beans budget doesn't mean you only have to eat beans as rice and beans! There are lots of different ways to serve beans, including in soups, in burritos, hidden in baked goods, and as part of a sauce. Dried beans can be ground into flour. In addition, mung beans and lentils are excellent for sprouting. Mung beans are the beans that are grown to make the beans sprouts you see in stores. Lentils can be spouted and used in the same way. Soybeans can be used to make soy milk (with a soy milk maker) and that milk can be used to make tofu. Cooked beans are an excellent first finger food for babies (and bean broth can be fed to smaller babies).
Build a good variety of beans in your storage. White beans (navy or Great Northern or both) have great versatility. They can be used in place or milk in cream sauces and soups, or even in place of oil in cakes. Navy beans are the beans used to make baked beans. Black beans are more meaty in flavor, making them great in burgers and burritos. Pinto beans are fantastic in burritos and as "rice and beans". Lentils require no pre-soaking, and are a quick way to make a meal, whether with rice, vegetables, and spices, in soups, or in tacos.
If you're cooking with beans, some forethought is required. Beans should first be rinsed (just as you would with any vegetable) to get off any dirt. Most cooking methods require that you soak the beans for 6-8 hours, or overnight, before cooking them. The water is then drained, fresh water is added, and the beans are cooked, whether in a pot or a crockpot, for several hours. If you cook the beans in a pressure cooker, you will only have to rinse them; no pre-soak is required and they will be done cooking in less than an hour.
Do NOT add salt to your beans until they are finished cooking, or they will never soften. If you have older beans (more than 10 years) in your storage, you can add some baking soda to the cooking water to help the beans to soften.
If you cook large batches of beans at once, you can freeze extra cooked beans to use another day, thereby shortening your cooking time for the next meal. If you have a pressure canner, you can also can your own beans. I usually cook 10 cups of dried beans at once.
Check out the links below for excellent resources on how to cook beans:
Cooking chart for COOKING dried beans using a pressure canner Different times for different types of beans. The list of beans here is extensive.
Beans can also be cooked in the crock pot.