P.M.
My introduction to nutrition came 35 years ago when I started getting headaches every day. I found out they were sugar-related and banished sugar entirely from my home for many years after that. My daughter did not taste refined sugar or candy for her first 2 1/2 years (and grew up loving fresh fruit).
For me, lifestyle changes are easiest if you focus on just one thing at a time, but really focus. I started with sugar, then a few months later started cooking more fresh vegetables, experimenting with preparation techniques until I found some I actually liked, then moved on with other foods. I couldn't afford organic (and it wasn't much available) until years later.
I've also found that it doesn't work too well to completely banish favorite foods, so your husband might have a hard time adjusting unless you allow reasonable amounts of pizza and ice cream. But you can gradually increase the proportions of healthier foods as you discover "new" favorite meals and treats. And you might be able to keep your boys from developing a soft-drink habit.
I don't use cookbooks, but I'll bet there are lots of good ones at health/nutrition stores. There are also prepared frozen dishes in their freezer cases that serve in a pinch when you want to avoid eating out (which tends to get awfully expensive, and time-consuming when you are herding young children). And I just googled "nutrition, recipes" and instantly got a long list of free resources.
Good luck! This is a wonderful thing you are doing for your family.