Some useful webcasts to get started with BizTalk R2:

BizTalk 2006 R2 Technical Overview (Mitch Stein)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-01&pw=BTS06R2

Building EDI Solutions with BizTalk Server 2006 R2 (Tony Bernard)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-02&pw=BTS06R2

Orchestrating the real-time enterprise with the BizTalk RFID platform (Anush Kumar)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-03&pw=BTS06R2

AS2 Adapter & EDI Business Value (Tony Bernard)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-04&pw=BTS06R2

Building device providers for the BizTalk RFID platform (Anush Kumar)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-05&pw=BTS06R2

Designing and deploying BizTalk RFID Business Processes (Anush Kumar)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-06&pw=BTS06R2

Using BAM Interceptors for WCF and WF (Brad Paris)
http://www.livemeeting.com/cc/microsoft/view?id=Jumpstart-07&pw=BTS06R2