On one side, I list the foods that I have already that need to be eaten up. Then I can decide what I want to make for dinner during the week, and what other things need to be bought to make those dishes.
I also list my dinner plans on the bottom, in case I forget what I wanted to make by the time dinner rolls around. Then I know for sure that we have enough ingredients to make those things, even if it ends up being a different day that we eat them. (i.e. tonight? We're having Joy the Baker's soup that I'd planned for Saturday. I'll tell you more about that later!)
This notebook has really helped me stay more organized, and have less produce go to waste. When I don't use it to prepare the week, we end up with a lot more trips to the grocery store during the week. I fully recommend using something like this if you'd like to save some shopping trips and money!