Even though C# is a relatively new programming language, many useful sources of C# information exist on the Internet. In my view the following three resources are particularly valuable:
http://msdn.microsoft.com/net This is the .NET part of the Microsoft Developer Network (MSDN) Web site. Here you will find the latest language specifications, documentation, and technical articles about C# and .NET.
http://www.devx.com/dotnet/resources/ This site contains a comprehensive list of .NET and C# resources on the Internet.
http://discuss.develop.com/dotnet.html While this discussion group is not targeted at beginners, it is frequented by some of the key C# and .NET designers from Microsoft, along with many other highly-qualified C# programmers. As you read through this book, you will likely begin to appreciate the interesting and useful contributions found here.