While exploring options for integrating BizTalk and SharePoint, I stumbled upon the following BizTalk Server 2006 related posters! For sure, a picture is worth a thousand words.
BizTalk Server 2006 R2 Database Infrastructure Poster
Microsoft BizTalk Server Operations Guide
BizTalk Server 2006 R2 Capabilities Poster
BizTalk Server 2006 R2 Runtime Architecture Poster
I also came across the BizTalk Server 2006 Tutorials and the BizTalk Server 2006 Installation and Upgrade Guides