Microsoft has released 2007 Office System: How Do I ScreenCasts

This download presents screencasts of the following topics:

Building ASP.NET Web Parts for Windows SharePoint Services 3.0 (AspWebPartsForWss3.wmv)
Creating and Customizing Site Pages with SharePoint Designer 2007 (SharePointDesigner.wmv)
Creating and Testing Features with Windows SharePoint Services 3.0 (WssFeatures.wmv)
Creating and Using Content Types in Windows SharePoint Services 3.0 (ContentTypes.wmv)
Creating and Using Event Handlers in Windows SharePoint Services 3.0 (WssEvents.wmv)
Creating and Using Site Columns in Windows SharePoint Services 3.0 (SiteColumns.wmv)
Creating and Customizing Document Information Panels with InfoPath 2007 (DocInfoPanel.wmv)
Creating Custom Workflows with SharePoint Designer 2007 (SpdWorkflow.wmv)
Custom Task Panes in Microsoft Visual Studio Tools for Office "v3" June CTP (VSTOCustomTaskPane.wmv)
Customizing the Ribbon with Microsoft Visual Studio Tools for Office "v3" June CTP (VSTORibbon.wmv)
Extending the Office 2007 User Interface with a Custom Ribbon (ExtendedRibbon.wmv)
Extending the Office 2007 User Interface with a Custom Task Pane (CustomTaskPane.wmv)
Getting Up and Running with Excel Services (ExcelServices.wmv)
Generating Office Documents using Office Open XML File Formats (OpenXMLFileFormats.wmv)

2007 Office System: How Do I ScreenCasts