You can see Safeway’s coupon policy right here. Most stores will allow you to stack a manufacturer coupon with the store coupons that can be found in the weekly circulars. You will want to be sure to get a club card to take advantage of the sale prices!
Safeway sale prices tend to vary from region to region so you will always want to double check your local ad! Also, I do not have double coupons in my area so your prices are likely much better than mine!
And you can see the current list of Safeway catalina offers here.