Useful links

Documentation and specification

C# documentation — official C# documentation with guides and a reference
C# language specification — a formal description of C# syntax and semantics
What's new in C# 14 — new features in the language version included with .NET 10
.NET documentation — documentation for the .NET platform, runtime, and tools
.NET API browser — search .NET library classes and methods with examples
C# coding conventions — recommended C# naming and code formatting conventions

A tour of the C# language — a brief overview of types, classes, generics, and other language features
Object-Oriented programming (C#) — encapsulation, inheritance, and polymorphism through C# examples
Collections and data structures — choosing generic collections such as List, Dictionary, and HashSet
Language Integrated Query (LINQ) — querying collections and data with LINQ
JSON serialization in .NET — serializing objects to JSON and back with System.Text.Json
Unit testing in .NET — writing and running unit tests with MSTest, xUnit, and NUnit

Visual Studio documentation — working in Visual Studio: projects, the editor, and builds
Debug C# code using Visual Studio — step-by-step debugging of C# programs with breakpoints
Git Reference Manual — official command reference for the Git version control system
SharpLab — run C# code online and view IL and expanded code

Exercism C# Track — exercises with automated checking and mentor reviews
Refactoring.Guru — Design Patterns in C# — illustrated explanations of design patterns with C# examples
.NET Blog — official news and articles from the .NET team
.NET YouTube channel — video tutorials, .NET Conf talks, and livestreams from Microsoft