I think the first question people ask about shopping with coupons is why do it? There a quite a few reason, but the biggest answer for me is because I save a TON of money and get a LOT of groceries! I started shopping with coupons about two years ago after we moved into our new home and our mortgage payment was a tight fit. We cut our food budget in half and it made a huge difference.
Besides the whole money issue, we've been able to actually build up a decent food storage. BC (before coupons), we had a pretty sad pantry. I might pick up an extra can of this or box of that, but I didn't have much. Granted, at the time I had a tiny pantry and couldn't fit a lot of extra food in there anyway, but it was still pretty sad. Now, I'm finally building up a good stock-pile of food my family likes and best of all, I'm getting the food for cheap!
A little while ago, our city had a boil order on water due to some contamination. People were flocking to the stores buying up all the bottled water and stores could hardly keep up with the demand. I never went to the store once that week since I had 7 flats of bottled water as well as a few liter bottles. We also had a stash of juices and punches for the kids. That was nice.
There are other reasons to coupon shop, and I'll address more of those in the future, but I just wanted to share a few of the main reasons first.