Or buy a sandwich from the deli in the grocery store. It's cheaper than fast food. Library, library, library, and of course the internet. They provide the books and magazines for free. If you don't see a certain book in the library, ask the librarian to check the other area libraries, they do it via computer, and have it in a couple of days usually.
Prepared food tends to cost alot.
Don't buy prepared, learn how to make it. Trade toys, clothes etc. Instead of buying napkins, use a wet washcloth. This is especially great with kids for meals or art projects. Also using cloth diapers is cheaper than disposables.