I make my own food for my dog. Before I used to buy commercial dry food, but I think it's full of chemicals and you don't really know what's in it.
Recently I found this
Healthy Food For Dogs: Homemade Recipes book and I'm trying to make food for my dog according to this. And I like it better than the dry food from the shop.
I'm sure there is a lot of similar books so maybe you can try one of them.