You might also want to check out Anthony Bourdain's Les Halles Cookbook. It has a lot of the classic French bistro-type recipes, including some cheats for home cooks that you might not find with Julia Child, plus it has a nice sprinkling of his trademark snarky commentary.
15-20 cook books
I don't use any on a regular basis, I like to read them and learn cooking techniques and flavor balance ideas to incorporate into my cooking
Books I'm excited to read/use:
Start with this cookbook
Anthony Bourdain's Les Halles Cookbook: Strategies, Recipes, and Techniques of Classic Bistro Cooking https://www.amazon.com/dp/158234180X/ref=cm_sw_r_cp_api_pyWeAbK4J2TDM
buy it, you'll fucking love it https://www.amazon.com/Anthony-Bourdains-Halles-Cookbook-Strategies/dp/158234180X