Q&A Forums
There are many general public VB.NET Q&A forums, but the Microsoft MSDN section for VB.NET is one of the best at http://forums.msdn.microsoft.com/en-US/tag/visualbasic/forums/. The VB.NET section at Xtreme VB Talk is also good, and it includes a subforum for .NET Office automation at www.xtremevbtalk.com/forumdisplay.php?f=97.