http://www.moneysavingmom.com/
This is a fantastic resource for coupon match ups on sale items for all our local grocery stores. Most of my coupon match ups come from this site. She has links to coupon forums and information on Free Samples daily.
http://www.hotcouponworld.com/forums/view.php?pg=price_book_walmart
Hot Coupon World has a near complete price list with search capabilites for Walmart items.
http://www.thecouponchallenge.com/2010/03/my-goal-meat-prices.html
List of goal meat prices. Very helpful when evaluating sales.