How to learn C#

An overview of how to get started from scratch with C#

Websites

The official C# documentation has great content on a wide variety of subjects, including tutorials and a tour of the language.
Learn C# is an interactive, in-browser tutorial that introduces you to the core concepts of programming in C#.

C# 101 The concepts and syntax of the C# programming language with live coding demos.
.NET Core 101 Ins and outs of "What is .NET" and how to publish your very first application.
Programming in C# Jump Start is a nice step-by-step introduction to programming in C#.
C# Fundamentals for Absolute Beginners is a great way to get to know C#.
PluralSight has several great introduction courses. The downside: PluralSight is a paid service, but you can request a free trial.