There are a lot of good sites to print coupons from. Here are some of the better ones:
Also, here is a coupon site you should find really helpful.
They have a database that lets you search for specific coupons for items you may have on your shopping list. It will show you all available coupons for the product and direct you to the sponsoring website (most of the time the manufacturers website), to print it off. This site is also great at keeping you up to date on the latest deals, promotions, free stuff, samples and more.
Best of luck couponing!!!