An NGO has produced an excellent guide to basic, cheap, healthy cooking: Good Food on a Tight Budget. Their press release announcing it and giving some other info is here.
I have reviewed it, and aside from a few little details, it is very good. It starts with a guide to foods that are cheap and healthy, and then gives recipes. If I were to write a guide to how I shop and cook, it would look very much like this. My diet basically consists of about half of the foods they recommend, and about half of their recipes they show. I plan on experimenting with the other half.
There are so many good points. They tell you how to make salad dressing. They recommend yogurt and tell you how to make good things with it. They recommend eggs. They give the basics of making oatmeal.
Most of the people in my family will know much of this, but I would still recommend that you read it as a refresher, and to pick up a few tips. You should definitely bookmark it as a reference, and have it handy to send to friends. Following this guide will tell you how to feed a family well on a budget that is smaller than SNAP benefits.
If you are not a healthy eater, you can use this guide to make a few easy changes to your diet that will have big rewards. I'd recommend starting with replacing your snacks and desserts with their yogurt parfait recipe. Then follow their advice for healthier breakfast foods. Just make one easy change every couple weeks or so, and within a year you will be feeling a lot better and your health will improve.
Information like this is the best way to improve the health and quality of life of people in this country. If everyone had this knowledge and acted on it, then people would never go hungry, and most of the health problems in the country would go away.
Now, for the nitpicking:
The biggest problem is that they push organic foods. There is no good evidence that organic foods are any healthier, or that the levels of pesticides in normal foods cause significant harm. If you are poor, you do not need to be spending money on organic foods. The health gains from lowering pesticide exposure are tiny, if they even exist, and there are many, many things that are a better use of your money.
They say, "Buy brown rice in bulk and mix with white rice if needed to lower cost." This is bad advice. Brown rice needs to be cooked about twice as long as white rice. If you mix different types of rice, you will get a nasty hash of overcooked white rice and undercooked brown rice.
Typo alert: they have 'mungo beans' when they should say 'mung beans'.
They really should have produced a printer friendly version without all the background graphics. This is something that I would like to print several copies of to give to people. This is something that you might want to print dozens of copies to to give to people in your church.
I am guessing that some of the foods they recommend would cease to be cheap if more people started buying them. There is only so much starfruit and squid to go around.
They assume you know basic cooking tasks like how to peel and chop vegetables. This can be hard to figure out on your own, and it is very easy to get disappointing results and get discouraged. Even experienced cooks like me and my family sometimes have trouble dealing with the exotic Asian or Hispanic things we buy as experiments. You need to learn food preparation by seeing someone doing it. There is a learning curve to cooking, and this guide will not get you past it if you are a complete novice. They should have recommended a cooking show for people to watch for tips. I have no idea which show is best, but I know there must be some good ones out there.