SQL Server 2012 Availability Groups in Azure, Step by Step
Coming soon – a step by step guide to setting up a SQL Server Always-On Availability Group lab environment in Azure Virtual Machines.
Edit: Turns out Microsoft has already documented this thusly.
High Availability and Disaster Recovery for SQL Server in Azure Virtual Machines (Updated: June 4, 2015)https://msdn.microsoft.com/library/azure/jj870962.aspx
Tutorial: AlwaysOn Availability Groups in Azure (GUI)