There are a LOT of ways one can try to save money on their grocery bill.
1. clip coupons
2. shop a variety of stores for sales items
3. stock up during a sale
I'm sure many of you could add a lot more to that list. Meat, milk, bread, that type thing, I find it harder to get a good price on. Meat goes on sale, but there are some staples that really don't. Eggs might be another example, though they go on sale, it's not normally by much. You can't really stock up on most staples, either. You can stock meat if you have a freezer, but otherwise, you can forget it (we do have a freezer but unless it's fish or chicken, I like fresh).
For coupons though, there are SO many online sources you can turn to. A lot of these sites have the same coupons as the others, but sometimes, they do have exclusives, or coupons that other sites just don't have. Sometimes the store will double them, sometimes not. I know the main store where I shop doubles the first coupon of a given product, but will not double subsequent coupons for the same item. If you live close, maybe you could make different trips during the week to take more advantage of that (personally, I think that would be a pain, but I've heard that some people do this).
The Consumer Reports Shop Smart Guide for July listed these 3 sites, but there are a LOT more out there
www.SmartSource.com www.Coupons.com www.Coolsavings.com They even recommend that you visit the websites of the stores where you shop. First, you can view the weekly circular, but they might also have other deals and/or coupons listed on the site somewhere (I know my favorite store has specials if say you buy 4 of these, you save $3 at checkout, and they also have their own coupons listed there).