I cannot believe I just overlooked this link for so long. I have announced back in May that the VB Upgrade Guide is available in print, but I forgot to mention that it is also available for download at MSDN.
Link to Upgrading Visual Basic 6.0 Applications to Visual Basic .NET and Visual Basic 2005
This is a great resource to understand how to perform the upgrades. In addition, if you are looking for the VB Companion mentioned in the guide please go to: http://www.artinsoft.com/pr_vbcompanion.aspx it substantially reduces the cost of an upgrade.
I'd like to hear comments on the usefulnness of the guide. Let me know!