I'm fairly new to couponing, but I belong to an internet site thegrocerygame It does cost to belong, but they will tell you the regular price, sale price, the coupons to couple with the sale price to get the best deal and the percentage you will save. It helps me a lot to know if I am really getting a good deal.
Couponmom is another good coupon site. Also you can go directly to Red Plum and Smart Source (the coupons that come with the Sunday paper) to get coupons.
A good free site to go to is kcpenneypinchinmama. You'll get coupon recommendations for many stores for the week and you will get lots of info for other coupon clipping sites.
Have fun...couponing really does become a game to see how much you can save once you really get into it!