That's an easy one. Every other Wednesday, in place of Question of the Day, we run a new Reader Poll; the following Saturday, we post the results for the previous survey. On the day that a new poll goes live, it occupies the spot where QoD is normally -- the second button down in the middle "Features" column on the home page.
After 24 hours, the space goes back to being home to QoD, but you can still access and vote in the poll via the blue icon on the left-hand side of every page. Just click Add Your Vote to access the current question and voting options. (The one running right now concerns your thoughts about The Linq, the big new center-Strip development proposed by Caesars Entertainment.) For previous polls, which are open to everyone to read, click View Previous Polls at the bottom of the current one to access the archives.