Start a new thread, fill in a title, and then write something in the post-box.
Then like Doorknob said, scroll down the page, (before clicking "submit") and you'll see another box of "additional options".
The second choice from the bottom has a "start poll option", you click that, then select the number of choices you want, then click the "submit" button at the bottom of that options menu.
Then you'll be taken to a page to make up a question, and fill in the choices you want, and how long you want the poll to run. Then click "submit" again, and you're done.
