Useful TechNet links for Planning, Designing; Securing an Extranet (SharePoint Server 2007)

 

Plan authentication methods (Office SharePoint Server)

http://technet.microsoft.com/en-us/library/cc262350.aspx

Design extranet farm topology (Office SharePoint Server)

http://technet.microsoft.com/en-us/library/cc263513.aspx

Downloadable book: Planning an Extranet Environment for Office SharePoint Server

http://technet.microsoft.com/en-us/library/cc262400.aspx

Planning, Designing; Securing an Extranet and Internet Facing WSSv3 and SharePoint Server 2007 Environments

http://blogs.msdn.com/sharepoint/archive/2006/08/08/planning-designing-amp-securing-an-extranet-and-internet-facing-wssv3-and-sharepoint-server-2007-environments.aspx

External Collaboration Toolkit for SharePoint

http://technet.microsoft.com/en-us/library/cc268155.aspx