Check out these links I found for free coupons:
Delmonte: Sign up to recieve $35 in coupons. This also includes recipes, nutritional advice and healthy lifestyle tips
Betty Crocker: Sign up for the Dinner Made Easy email newsletter and recieve a free booklet with $10 in coupons.
Fiber One: Sign up and recieve a free sample of Fiber One Honey Clusters, Fiber One Oats and Chocolate Bar and a coupon booklet with $3 in savings. (Those Oats and Chocolate bars are yummy, they will certainly satisfy the late afternoon munchies!!)
Home Made Simple: Sign up to recieve a coupon booklet with over $27 in savings.