I came across this blog today, where a mom feeds her family for only $40 a week! Although I'm inspired, the amount of time this takes to cut coupons, get multiple copies of newspapers (for all the coupons) and going to the different stores can amount to a whole part-time job. However, maybe you really enjoy doing that and this could help you!
One of the most helpful things I found on her site was a two-week menu (breakfast, lunch and dinner) that would only cost between $35-$60 a week! She also gives weeks and weeks of other menus she has used within that same price range. Just click on this link and you can see her menus. They actually look really good and are comprised of foods my kids would actually EAT!
This site also has a link to Swagbucks, which my friend Anna told me about. You get "swagbucks" for searching online through their search engine (which uses google), and you can use these "dollars" to actually buy items (like points). This is a great way to earn real products just by searching for things online! (Another site which works similar to this is MyPoints, which I use and have gotten $50 gift cards from!)