Get a head start on Winter ’08 with the latest Force.com Developer Guides:

• Visualforce Developer’s Guide – in HTML or PDF
• Apex Developer’s Guide – in HTML or PDF (formerly known as the Apex Code Language Reference)
  • including an AppExchange package of code samples
• Force.com Web Services API Developer’s Guide Version 11.0
  • including the Winter ’08 API Release Notes 
• AJAX Toolkit Developer’s Guide Version 11.0

For details about what’s new for Visualforce and Apex, see the Winter ’08 Release Notes. And check out the Documentation page on the ADN wiki for all your developer doc needs.