These three titles have been released on MSDN for free, or you can purchase a hard copy or eBook as well. Great references for Windows Azure development

A Guide to Claims–based Identity and Access Control

http://msdn.microsoft.com/en-us/library/ff423674.aspx

Moving Applications to the Cloud, on the Microsoft Windows® Azure Platform

http://msdn.microsoft.com/en-us/library/ff728592.aspx

Developing Applications for the Cloud, on the Microsoft Windows® Azure Platform

http://msdn.microsoft.com/en-us/library/ff966499.aspx

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