if you know how to read you know how to cook
Well you know how to follow a recipe. What about making something of your own? When do you use high heat? What about substitutions?
I agree that good books are essential for those who don't have an education in cooking, but you want books which not only give you a list of ingredients, but the why's of what you are doing.
I'd suggest getting a subscription to Cooks Illustrated. I have some books by Julia Child including her two on French cooking. Rick Bayless on Mexican food, books on regional italian cooking, perhaps a hundred cookbooks and three bookcases of magazines going back to the mid 80's and yes I've read them all.
I'm sure Magnus can make some recommendations, but when selecting books about food remember that understanding why a thing is done is as important as combining a laundry list of ingredients. In fact it's more so.
Take baking. It's fundamentally different than making savory dishes, which is different than working with chocolate and understanding tempering.
When you are making a basic loaf of bread (and I mean the real stuff), the ingredients are simple, however the quantities aren't meant to be approximated. Small differences in amounts and technique will make a vastly different product. Even the humidity in the air can cause considerable variance.
To reduce inconsistencies I prefer weight based recipes for baking. So many ounces of flower per batch rather than volume.
Get the basics down and understand the concepts. Don't be an automaton who cooks by written algorithm.