Being the first book I read to learn C# (I had learned it a little by hanging around stuff in Visual Studio and MSDN Library before reading this book), it was great! It's great for an absolute beginner to programming to someone who is experienced in programming but new to OOP or new to .NET or new to C#. It's not very useful for a professional C# guy. Actually it contains a bunch of mistakes and there are many important concepts not mentioned at all. By all means, it's a great book for anyone new to the language or the framework.