Since we've been without a new cooking thread for a bit and the old OP had a fair share of outdated links, I figured it was time for a new one/add some my favorite food resources.
Whether you're new to cooking and just want to know what to do with something you just bought at the grocery store, trying to figure out the difference between German, French, and Japanese chef's knives, or not sure if a bearnaise or chassuer sauce would be better for your sous vide cooked beef, this is the place for all manner of cooking discussion and food porn of your creations.
Serious Eats: Covers a bit of everything about food and cooking but Kenji Lopez-Alt's Food Lab stuff and Stella Parks's articles are especially renowned for going into the science behind their techniques
Food52: A mix of community recipes and staff written contributions. Alice Medrich is often credited/blamed with introducing chocolate truffles to the US
The Kitchn: Obviously recipes but also a lot of stuff about equipment and kitchens as a room in the home
All Recipes: User submitted recipes ranging from beginner to advanced
Epicurious: Another recipe repository plus articles and roundups
The Pioneer Woman: Not as prolific, seems to have shifted to doing videos with her recipes
Hip Pressure Cooking: Whether you're a long time fan of 15 PSI or just got an Instant Pot, this is a great resource for pressure cookers
Chef Steps: Some stuff require a paid account but much of it available to free accounts. A great online resource for modernist cooking with plenty of uses for sous vide techniques, modernist thickeners, blenders, and other enthusiast stuff
Ricardo Cuisine: A well known Quebec chef recommended by @Richy , previous cooking thread author who gets great use out of the 30 minute or less section on weeknights and recommends halving listed sugar amounts in desserts.
The Joy of Cooking: Possibly the only cookbook with instructions on both Creme Brulee and how to prepare a squirrel for cooking.
How to Cook Everything by Mark Bittman: Another diverse resource by the long time writer for the New York Time's cooking section. Great for beginners.
I'm Here Just for the Food by Alton Brown: Goes into the science behind a lot of cooking and has a good information on equipment for people just starting to stock their own kitchen. Another good one for beginners.
Cooking for Dummies: Obviously aimed at beginners.
The Essential Vegetarian Cookbook: Other people say it's useful so it's being included.
Sweet Cream and Sugar Cones: The Bi-Rite Creamery's book of ice cream and frozen treat recipes. Great for anyone with an ice cream maker.
BraveTart: Iconic American Desserts: Stella Parks's book of baking recipes released in 2017. In addition to detailed recipes and variations on many of them, it goes into the history of many popular desserts (eg, how the chocolate chip cookie was created way before Tollhouse came onto the scene)
Modernist Cuisine At Home: Modernist Cuisine is a multi volume set aimed at professional chefs that wanted to explore modernist cooking, formerly known as molecular gastronomy. This is their book aimed at enthusiast home cooks. A lot of recipes and discussion on sous vide, pressure cooking, modernist sauces, using dry ice to make ice cream, and the like. Warning - this book will make you lust after some very expensive kitchen equipment.
Heston Blumenthal At Home: More advanced than previously listed books and Heston is British so some ingredients need to be subbed outside of the UK, but the section on sauces alone is wonderful.
The Flavor Bible: Not a cookbook, more like a pantone swatch book for cooking. Lists of flavors that professional chefs have found work great with others. Handy when you know you want to cook x thing but don't know what herbs and spices or side items to use with it.
Flour Water Salt Yeast: The Fundamentals of Artisan Bread and Pizza: Enjoyed by @dispatch.o for delivering carb goodness.
A number of the previously listed websites have youtube channels worth checking out or otherwise frequently post them but there are also a plethora of other video channels worth checking out. Plus it's often handy to see what your food is supposed to look like at different stages.