I came across the following link when I wanted to use NHibernate with Azure Table Storage;
http://cloudshaper.wordpress.com/2010/10/24/getting-started-with-nhibernate-on-azure-table-storage-services/
You will need a driver which is available from Codeplex
http://nhazuredriver.codeplex.com/
If you want logging then this link will help
http://cloudshaper.wordpress.com/2010/10/
I have not tried this yet - that fun is yet to come ;)