I am starting to work on a really interesting project where BizTalk and WCF will be the keys.
I have used in the past WCF and I am not worried about it, I like it and it’s better than the old Web Services.
Unfortunately I know BizTalk but I still do not master it. Over the network I didn’t find anything really useful but Microsoft has tons of tutorials and how to.
- Overview of BizTalk 2009 http://www.microsoft.com/biztalk/en/us/roadmap.aspx
- Getting Started http://msdn.microsoft.com/en-us/library/aa560946%28BTS.10%29.aspx
- Step-by-step with some databases (Oracle, Siebel …) http://msdn.microsoft.com/en-us/library/aa560946%28BTS.10%29.aspx
- Common Tasks http://msdn.microsoft.com/en-us/library/aa548054%28BTS.10%29.aspx
- Complete guide to BizTalk 2009 http://msdn.microsoft.com/en-us/library/aa548004%28BTS.10%29.aspx
Also, if you need to start with WCF and the NET Framework 3.5, here is what I have found over the network:
- Overview http://msdn.microsoft.com/en-us/netframework/aa663324.aspx
- Beginner http://msdn.microsoft.com/en-us/netframework/dd939784.aspx
Probably in the next days I will start to evaluate some books about BizTalk 2009 and WCF. If anyone of you want to ask me to evaluate a book about WCF or BizTalk, I would really appreciate. 
Stay tuned!