Asli Bilgin has put together a great list some VSTO resources (by no means comprehensive so please comment with any other resource not here that you like):

bits & bytes

·   Get Microsoft Visual Studio 2005 Tools for the 2007 Microsoft Office System

·   Visit the Visual Studio Tools for Office Forum

·   Visit the VSTO Developer Center

·   Get the OBA/VSTO Starter Kit v. 1.0

·   Try the O2 OBA Challenge

·   Visit OBA Central

webcasts

·   MSDN Webcast: Visual Studio Tools for Office Straight from the Experts: Ken Getz (Level 200)

·   MSDN Webcast: Visual Studio Tools for Office Straight from the Experts: Robert Green (Level 200)

·   MSDN Webcast: Visual Studio Tools for Office Straight from the Experts: Tim Huckaby (Level 200)

·   MSDN Webcast: Visual Studio Tools for Office Straight from the Experts: Paul Ballard (Level 200)

Blogs

·   The nicest man at MSFT (and he plays a mean guitar too): Mike Hernandez Blog

·   Paul Stubbs – Senior Program Manager

·   VSTO2 blog

·   Best of VSTO blogs

·   Brian Goldfarb, Group Product Manager – he can demo a fetching VSTO

·   Chris Castillo's WebLog

·   John Durant

·   Tim Huckaby

·   Ken Getz blog

·   Kathleen McGrath

·   Paul Stubbs

·   Paul Ballard

Tech talks

·   VSTO and securityEric Lippert, VSTO team, senior software dev engineer

·   Scope of VSTO Martin Sawicki, program manager VSTO

·   Why a VSTO Runtime?  Thomas “TQ” Quinn – Principal Architect & Christin Boyd – Customer Program Manager (she KNOWS things, just ask her)

demos

·   Video Demo: VSTO and VBA Interop

·   How Do I Videos

·   VSTO demo Catherine Heller, Technical Evangelist – Windows Live

·   Extend VBA with .NET  Eric Schnepp, Principal Program Manager in the VSTO team

labs

·   MSDN Virtual Lab: Building Custom Office Applications Using Microsoft Visual Studio Tools for Office Part 1 - Data Binding with Word Content Controls

·     MSDN Virtual Lab: Building Custom Office Applications Using Microsoft Visual Studio Tools for Office Part 2 - Create an Outlook Add-in with a Form Region

·    MSDN Virtual Lab: Building Custom Office Applications Using Microsoft Visual Studio Tools for Office Part 3 - Build an Excel Add-in with Ribbon and Custom Task Pane Integration

MSDN Virtual Lab: Building Custom Office Applications Using Microsoft Visual Studio Tools for Office Part 4 - Create a SharePoint Workflow