I think one of the things you have to consider here is that you need to find some suggestions that are sustainable for a real-life family, not an ideal family. So i'm afraid I disagree with some of what RGM2 has to say. Portion control??? make a pot of lentil soup and let the kids eat all they want!!! you don't want to control portions of good, healthy food. And planning for a month? we're talking about families here, with all the vicissitudes of everyday life, kids getting sick, parents getting sick, kids having after school activities, kids going to a friend's house for dinner, or a relative's, how can you plan a month in advance? Only restaurants can be expected to do that. I can't plan from this morning to tonight, so planning a month in advance is not going to be something you can easily get people to do.
But something more useful for REAL life is that you can make lists of staples that can make a meal at any time. What should be BOUGHT every week, or should be in the house.
Some will have to be quick things made at the last minute. Some can be for a day when someone in the house has the time or inclination to make a big pot of something for a few days.
Celery, carrots, onions, garlic, oil, dried lentils, canned chickpeas (why canned? because if you're trying to get people to cook who usually just open a can, you'll have to make it easy. No one who never cooks is going to soak chickpeas overnight), pasta, rice, eggs, flour, potatoes, maybe frozen spinach, frozen peas, salt, pepper, favorite seasonings (these are cultural factors, people like what they like),
Cornmeal, buckwheat, cabbage, okra, eggplants, etc, are probably more culturally determined too - you can't change a person's style of eating overnight, nor should you. There should be recipes for every culture, that will appeal to every culture. Yoiu could get your kids to ASK THEIR GRANDPARENTS, NEIGHBORS, FRIENDS for recipes, maybe get THEM to help you make the cookbook for them. That sort of participation will be a big incentive, to be involved in the process
Then some of the easier things to make from scratch should be taught. Tons of people think you can only make mashed potatoes from a box. It isn;t hard to make them fresh. If you peel and cut up the potatoes first, it isn;t too time consuming (tired mother coming home after a long day doesn't have the time to boil whole potatoes, then wait for them to cool enough to peel)
Pancakes can be made every bit as easily from scratch as from a mix, etc. I agree that breakfast has to be easy and fast - kids are unlikely to want to eat, and parents to cook, before getting a family out the door in the morning. Some special treats should be included, easy sweets that kids will enjoy making. You could also get them to make stuff like banana bread (easy and cheap) that can be brought for a snack to school or makes a good breakfast with a glass of milk. (most Italians have cookies for breakfast, when they eat it at all. Toast with jam is mainly wheat and sugar, cookies too, what;s the difference? But cookies go well with milk, and that's a good breakfast food)
Be careful of what appliances you presume the families have. Most won;t have a blender, food processor, maybe even cheese grater. I bet in this age of heating up in the microwave, many won;t even have a real oven.
Lunches are a big problem i hear, in the states, to the extent that a friend in california said her grandchildren were made fun of because they brought peanut butter and banana sandwiches for lunch and told they were eating 'HEALTH FOOD'!!! Yeah, it;s healthy, but when i was a kid it was a treat!
I think also you should look into the british cook who's set up a program for teaching poor kids to cook - Jamie Oliver. I haven't read his stuff or watched anythijng of his but I know he's involved in a program to get kids to eat better, and teaching them to cook. There are surely others, too, who could be a source and resource for recipes and ideas.