I know its dumb but do they send you a email or what plz help not that im gonna win
You can see the current leaders for the grand competition on the Cataclysm Stats Page. There is also a widget in the side of the main pages that sometimes lists the top 4.
Winners for all the weekly draws and overall competition are listed at Cataclysm Winners once they have been announced.
The random question/answer winners also get a comment on their winning post, which they'll see on their user page.
The winners also receive an e-mail to their registered address, and that is used to organise the prize.