SQL Server fails to Start-Troubleshooting the failure

Many times I see people asking in forums about SQL Server not started and how to troubleshoot the reasons for the failure to start the SQL Server.

This video explains the steps to troubleshoot the failures and find the error of a SQL Server startup failure. 
http://www.youtube.com/watch?feature=player_embedded&v=xkCqv6g-iSM#t=0