TSConfig Reference
Option-by-option documentation of tsconfig.json from the TypeScript team: strictness flags, module resolution, emit, JSX, interop and project references, each with examples, defaults and the version that introduced it. Use it to configure a project deliberately rather than copying someone else's file.
More resources on TypeScript
Type Challenges
Around 190 puzzles solved purely in the type system, graded warm-up through extreme, each with an online judge and published community solutions. Working through them builds real fluency with conditional types, infer, recursion and template literal types.
Effective TypeScript: 83 Specific Ways to Improve Your TypeScript (2nd ed.)
The field's bible for the gap between 'my code compiles' and 'my types are good'. Eighty-three short items on TypeScript idioms and pitfalls, revised for TypeScript 5, covering structural typing, inference, type-level programming, declaration files and migrating JavaScript. Finish it and you can judge competing type designs and say why one is safer.
Total TypeScript: Essentials
The best single guided path from 'I know JavaScript' to 'I am confident in TypeScript'. Editor-first method: it teaches you to read tsc's error messages and use hover types as the feedback loop, which is the transferable skill. Matt Pocock's sixteen-chapter book, free to read in full online, taking a JavaScript developer through annotations, unions, narrowing, objects, classes, modules, generics and tsconfig setup. Finish it and you can type a React or Node codebase unaided.
The TypeScript Handbook
The official documentation written by the language team: everyday types, narrowing, functions, objects, generics, conditional and mapped types, modules and project configuration. After reading it you can annotate code and read compiler errors without guessing.