Links: SharePoint

All Versions
Microsoft Office SharePoint Server 2007 products comparison download
Penny Coventry: Sharepoint Version Table
Heather Solomon: CSS Quick Reference
Heather Solomon: CSS Reference Chart for Sharepoint 2003

Version 3
Microsoft TechNet: Office SharePoint Server 2007
Microsoft TechNet: Upgrading to Office SharePoint Server 2007
Microsoft TechNet: Determine upgrade approach (Office SharePoint Server)
Microsoft Office Online: Microsoft Office SharePoint Server 2007 Frequently Asked Questions
Jason Medero: WSS V3/MOSS 2007 Upgrade and Migration from V2: Part 1 of 2
Jason Medero: WSS V3/MOSS 2007 Upgrade and Migration from V2: Part 2 of 2
Joel Oleson: Troubleshooting & Logs during a WSS/MOSS Upgrade
Shane Young: Upgrading from SPS 2003 to MOSS 2007 Beta2 TR using the gradual approach
Jonathon Frost: Preparing for a SharePoint Server 2007 Upgrade
James Henry: SPS 2003 to MOSS 2007 Upgrade Issues
William Baer: Understanding PRESCAN.EXE in MOSS 2007
Bill English: Moving SPS 2003 Databases to new SQL Servers
MSDN: Best Practices for Ensuring Application Reusability and Upgrade in Windows SharePoint Services
Joel Oleson: Best of... Upgrade and Deployment Guides for WSS v3 and Microsoft Office SharePoint Server 2007

Version 2
MSDN: Branding a SharePoint Portal Server 2003 Site: Part 1, Understanding the Use of a Corporate Brand
MSDN: Branding a SharePoint Portal Server 2003 Site: Part 2, How to Apply Your Own Corporate Brand
Dr. Dobbs: Sharepoint Web Part Development

Version 1
Microsoft: How to Create a Personal Dashboard in SharePoint Portal Server
Microsoft: Programs That Cannot Coexist with SharePoint Portal Server
Microsoft: Accessing a Workspace Using HTTPS Does Not Work, Dashboard Error -2147221499
Microsoft: Setup FAQ and Troubleshooting Guide
Microsoft: IIS Lockdown Tool Affects SharePoint Portal Server
Microsoft: Errors When Antivirus Software Scans Web Storage System
Microsoft: Indexing Web Sites on the Internet
Microsoft: Portal Displays Incorrectly When You Use FQDN
Microsoft: Required Properties Not Enforced During Bulk Check-in
Microsoft: SharePoint Portal Server and Storage Area Networks