C# 5.0 in a Nutshell can help you get started on some of the more advanced topics related to C# and .NET development.
Code Project provides a plethora of tutorials and sample code for C#/.NET developers.
.NET Rocks is an audio podcast that keeps up with the latest in .NET news and interviews successful .NET software developers.
Stack Overflow is a Q&A site with thousands of software development questions and answers covering C#, .NET, and many other technologies.
W3schools provides a SQL reference and tutorials.
ILSpy allows you to browse assemblies and decompile IL code back into source form.
LINQPad is a useful scratchpad for rapidly testing C# code without the need to put it into a project before testing.
scriptcs allows you use C# as a scripting language rather than creating full-fledged Visual Studio projects.
Mono provides the necessary software to develop and run .NET applications on non-Windows platforms.
Xamarin makes it possible to develop iOS and Android applications using the same C# and .NET source code.
Session 1 – Overview of .NET; Introduction to Visual Studio; Designing a Form; Object-Oriented Programming; Making the Form Do Something
Session 2 – Data Types; Control Structures; Debugging; Methods and Parameters; Events and Delegates; Exceptions and Validation
Session 7 – Handling Data Errors, More with Data Sources and DataSets, Creating Data Access Objects, Bonus Content (IDisposable), Menus, Toolbars, and Status Bars