The Joy of Cooking is a bit old but describes the practicalities of cooking fairly well. It's full of recipes yes but there's essentially an entire chapter at the start of each section that outlines different techniques and even how to select cuts of meat, etc. It's fairly basic advice but that + Salt, Fat, Acid, Heat will basically cover "intro to cooking" and give you a good set of the basic recipes to cover off.
I love the Joy of Cooking because it teaches cooking in layers. So it will start off teaching you how to make a simple dish, then the next pages are all permutations of that dish where you add a few ingredients, or slightly change the cooking technique.
