When you create a new thread, there will be three tabs near the top of the editor title "Discussion", "Question" and "Poll". Select the last option and type away. Note that you must put in a valid date and time for the poll to end, and the date is in DD/MM/YYYY format. Double check that your poll worked after posting because if the date is bad the poll will close immediately. It's a bit kludgey to use, so if you have any trouble getting the poll working just post a link to the thread here and I'll see if I can get it working.