These books are older so they focus on core language issues, and they have a VB6 to VB.NET perspective, but many of the concepts apply just as well to VB6 to C#.  

Books by David Ross Goben

Very impressive body of research by someone who was clearly an expert in VB6 and successfully made the move to .NET.  The problems are in the details, and David dives in.

Navigating Your Way Through Visual Basic 6.0 to Visual Basic.NET Application Upgrades (88 pages)

Enhancing Visual Basic .NET Applications Far Beyond the Scope of Visual Basic 6.0  (654 pages)

Microsoft Books

Upgrading Visual Basic 6.0 Applications to Visual Basic .NET and Visual Basic 2005