This is a very nice little introduction by this article lacks of several issues that should be looked at.

- certificate authentication

- mirroring replication

- linked server failovering

- job failovering

I had the experience with all of that for a client and I am still struggling with linked server. The failover partner solution does not work as there is a bug on Microsoft part (your login needs to be sysadmin for the linked server with failover partner to fully work). I am setting a different way as we speak as linked server is source of security breach. This needs to be definitely fix by Microsoft.