Here the work necessary for the amateur cook who seeks to go beyond the application (I take a recipe and I made what is written) to finally enter the stage of understanding, a necessary step when you want to control. Sure, it's big, it takes work to understand all the explanations, but to assimilate all principles are accompanied by recipes and examples.
If you love good food and want to give free rein to your creativity without following a recipe to the letter, while the gourmet, it will take some work, but you will have an excellent guide, and numerous recipes, at that.