Two other good sites are
pinchingyourpennies.com and the grocery forums at
fatwallet.com
Check out the Wishing Well in the Pinching Your Pennies forums. If you can post your wish list while the Wishing Well is open they will send you free coupons.
I can't stand not being able to access my coupons easily, and so I use a binder and put my coupons in trading card pages (got the idea at Fatwallet). It is so much easier to see what I have.
Depending on where you live you could try
cutouthunger.org This site has a matrix of grocery deals by state (but not all states). They list what sale items at the store coincide with coupons from the Sunday inserts. How much the item is, how much the coupon is, and how much you save.
You can print off coupons at
smartsource.com but some retailers won't take Internet coupons.
Valupage is also worth checking out. They don't have coupons, but they list specials that will kick out coupons for money off your next purchase at the register. At Albertsons, for instance, I may have an offer to get a 50 cent coupon for buying Children's Tylenol or something like that.
One thing I do is get an out-of-town paper on Sunday. Our paper inserts aren't all that great, but I've noticed that the bigger towns get some really good inserts with a lot more coupons. The paper I get is $1.75 but I more than make up that in savings from the coupons I get. Just compare them and see if that's the case for you. A couple of my friends also give me their inserts.
There are a lot of great sites that can help you save money.