You read the book first, which will tell you the recipes that are in the book. You don’t have to fully read the book, just read it that initial time – it should only take a few minutes. Then, if that book is within range and you have the required skill, that recipe appears in the crafting menu. If it’s not within crafting distance or whatever, you won’t have access to the recipes.
After you craft an item from a recipe contained in a book you have a chance to learn it, allowing you to craft it without the book.
