Along the lines of several recent threads, I thought folks would like to see this article from a local paper. It has some great tips. I'll add: shop the perimeter of the store where food is fresher, whole, less processed and therefore a much better value.
http://pressherald.mainetoday.com/story.php?id=193120&ac=
http://pressherald.mainetoday.com/story.php?id=193120&ac=