You post in the metagame discussion thread and the upcoming suspect discussion thread in order to vote for Doubles :0
http://www.smogon.com/forums/threads/np-doubles-stage-2-slumber-extended-to-mar-12th.3500138/
http://www.smogon.com/forums/threads/np-doubles-stage-2-slumber-extended-to-mar-12th.3500138/