All You magazine, one of my favorites, is having a grocery challenge contest beginning July 13th. Basically, you spend $25 per family member per week on groceries over a four-week period. The grand prize is a $1000 grocery card, a years worth of Knorr side dishes and a chance to appear in the magazine! HERE are the official rules.
If you are new to couponing, this magazine has just a ton of coupons in it. I generally don't pay for magazine subscriptions since you can get many of them for free throughout the year, but this one I will buy. You can also only buy it off the rack at Walmart. Go HERE for a deal on purchasing a subscription.