The last time I bought Cascadian Farm granola bars they were on sale for $2.49 a box. I had a $1.00 of 1 box coupon that doubled so I only paid $.49 a box. My grocery store has a limit of 3 like coupons so I bought 3 boxes at this price. The next week they were still on sale so I bought 3 more. These were printable coupons that I found online. I have 2 computers here so I printed 4 copies (limit 2 per computer) and my husband printed 2 copies at work. Udi emails me coupons a lot and recently had a promotion on facebook where if you "liked" them they would mail you a coupon for a free item. I signed up, my husband signed up, and my parents and inlaws signed up. GF bread is expensive, so I was excited for this deal! I'd say 90% of the coupons I use are found online and available in all areas. And it seems like more and more of the high value coupons are found on Facebook.
If you have a specific store you shop at try a google search. I shop at Kroger primarily so the day before I shop I google something like: Kroger matchups 2/26/12 and a bunch of websites come up that have a list of sale items with links to the printable coupons. Very easy and takes only a little time. I save about $90 in coupons every time I shop at Kroger. Mine does double more than most, but even if it didn't double that would still be $45 in savings. It really does help.