www.save.ca

You request coupons online, and the coupons are sent to your door. It's not specifically for groceries... but most of the stuff you can find at the supermarket.
Razors, Swiffer, oatmeal, chocolate powder, etc.

I've order coupons a few times already. And the deals are updated often so it's great (I'm in Ontario but I think BC's coupons are added regularly as well, as they're sent from the company). The savings add up :)