Posting a poll isn't as straightforward as I'd like, but it's pretty easy.

1. In the Polls and Surveys forum, click Write a New Post
2. In the text area of the Compose tab, type the following, including the brackets: [poll]
3. Click the Poll tab at the top
4. Check the box labeled, "Include a Poll in this Post"
5. Type your poll question in the "Question" box
6. Scroll down to the "Add Answer" box, typing in your poll answers and clicking "Add" after each one.
7. When finished entering questions, hit the "Post" button.

That's it. Not too tough, but that first part about putting in the "[poll]" string on the Compose tab isn't intuitive.