Nice DAX blogs to read about:

1. Cesar de la Torre - BLOG (A great Architect Evangelist, with deep technical and development knowledge in c#, AX, CRM)
   
   http://blogs.msdn.com/cesardelatorre
   
   Great article to read about .net business connector:
   Using Dynamics 'AX .NET Business Connector' to access Dynamics AX 4.0 from .NET world
   http://blogs.msdn.com/cesardelatorre/archive/2007/07/06/accessing-dynamics-ax-4-0-from-net-using-the-dynamics-ax-net-business-connector.aspx
   
   
2. Developing adapters using WCF
   http://blogs.msdn.com/sonuarora/archive/2007/03/26/about-wcf-lob-adapter-sdk.aspx