Web content management is a new feature in Sharepoint (MOSS 2007). These are my most important resources for getting information on WCM:

• Enterprise Content Management (ECM) Team Blog
  
• Microsoft SharePoint Products and Technologies Team Blog (managed by the Microsoft Sharepoint team, not specific to WCM but a great resource)
  http://blogs.msdn.com/sharepoint/
   
• ECM starter kit - great resource if you are looking for sample applications on workflow and some white papers. It's still in Beta 2 version but even so very helpful.
  
• Tools you should have when developing for MOSS on Visual Studio 2005:
  - Windows SharePoint Services 3.0 Tools: Visual Studio 2005 Extensions
  - Windows SharePoint Services 3.0: Software Development Kit
  - SharePoint Server 2007: Software Development Kit

There are also some other tools I like using when developing WSS/MOSS, I'll post these another day.