Most of my coupons come from the Sunday newspaper. Also you can usually find the current week's newspaper insert right in the store you are visiting. I've never printed any online coupons. I always just figured most of them were some kind of scam but thats just my skeptical nature.
I disagree with the whole concept of spending less and less on things like food. This will take more and more energy and is as addictive as gambling. Plus it has a distasteful pious undertone in some people. Cutting outgoings on groceries won't change your quality of life. But buying more expensive food will greatly improve it. And making money will definitely give you the chance to change everything in your life.