Chapter 3 of Kate Gregory's book, Microsoft Visual C++ .NET 2003 Kick Start, is available on The Code Project. This one covers the .NET Base Class Libraries.
Microsoft Visual C++ .NET 2003 Kick Start Chapter 3: The .NET Base Class Libraries
From the chapter:
The C++ Advantage - C++ can use the same class libraries as C# and VB.NET. Does it work the other way around? No. There are libraries of unmanaged code available from managed C++ that cannot be called from Visual Basic or C#—ATL and MFC are just two examples. However, it's unlikely that a Visual Basic or C# programmer would want to use those libraries, because their functionality is provided elsewhere; the capability to call them from managed C++ helps simplify a port from unmanaged to managed C++.