Aside from the newspaper coupons, I use coupons.com and you can check manufacturer websites for coupons as well.
I am not like the folks on Extreme Couponing (or whatever that show is called), as I don't have a GIGANTIC stockpile, but I do use some of their techniques. I couple the coupons I have with the sales papers for the stores I shop (Winn Dixie, CVS, Walgreens and Target) for deeper discounts. This weekends shopping trip netted me 2.5 weeks (17 days) worth of dinners and breakfasts, plus about a months worth of paper and cleaning products, a couple of months of toiletries and other snack and random food items, BEFORE coupons and store deals, the bill was $349.89, AFTER the coupons and store discounts it was $189.69. That is $160.20 in savings.
Mind you, the extreme couponers wouldn't think this was a deal, but I will be darned if I'm not THRILLED by saving 160 bucks! Before I started clipping coupons, I was spending in the $130 range EVERY WEEK on groceries and home items AND I was going back AFTER shopping during the week for items I had forgotton or toiletries or whatnot.
Anyhow, that was a long explanation of where I get my coupons, but.....there ya go!