Most books about cooking will walk you through recipes. If you’re lucky, by following the recipes, you will eventually work out something about the practice of actually cooking, and become a better cook.
This book – though it features recipes – is all about how cooking works. How to combine ingredients, and in what ratios to get different types of pastries, sauces, breads, even sausages. Without this book, I would never have had the courage to attempt to make pasta from flour and eggs (it worked).