If you're a VB 6.0 developer who recently moved(or is planning to move) to VB.Net, the IDE and debugger are a much stroger and meaner beast than ever before.
Debugging in Visual Basic .NET is a nice intro to all the cool stuff you can now do to debug your application. new C# developers will also find this helpful for their debugging tasks , if they don't mind reading some VB.Net code in the process.
This one goes right into my .Net debugging resources page.