So I signed up for BizTalk Server 2006 training with Dunn Training at the end of August.  I am somewhat familiar with the concepts behind BizTalk but have never really touched it.  Since we are currently using BizTalk 2004 in-house currently (upgrading to 2006 shortly), I wanted to familiarize myself.  I poked around the BizTalk developer center and found the BizTalk Virtual Labs.  This is the first time I tried these and found it to be a great introduction.  Microsoft actually hosts a Virtual PC they preconfigure for the lab that you access over the internet.  The development environment is loaded and so is BizTalk.  You just log on, run a script and follow the lab.  When I get some free time, I want to browse the rest of the Virtual Labs.