Currently I am studying the WCF-SQL Adapter. I found very informative webcast by “Thiago Almeida” about WCF-SQL adapter. This webcast belongs to BizTalk 2009, but for beginners it’s still good starting point. I don’t think things will not much different in BizTalk 2010 at least not at beginner level.
http://www.cloudcasts.net/ViewWebcast.aspx?webcastid=2521554268962766719