One of my favourite free Kindle books from last year...and one of the few cookbooks I've kept since downloading it...was Liss Burnell's 2012 Family Guide to Groceries Under $250 a Month.
It's free again (I just noticed that the DHM linked to it on today's Frugal Hacks post), and here's the link:
2012 Family Guide to Groceries under $250 a Month by Melissa 'Liss' Burnell and Budget101.com
Her earlier book is also free right now:
How to Feed a Family of 4 or More for Less than $200 a Month by Melissa 'Liss' Burnell.
As a bonus, here's one for homeschoolers. I don't know anything about it beyond the title:
Faithful Parents, Faithful Children-Why We Homeschool by Donald Schanzenbach