Do you mean adding a poll? When you create a thread look for the create a poll option. It's after create title. But you have to know what the grade is if it's actually graded. For a raw coin you're better off with no poll and asking for members opinions. We don't grade coins. We GTG - guess the grade. Everyone will give their best opinion on what they think the grade it could be.
Do you mean the part that lets you conduct a survey? When making a new thread there is a Post a Poll option at the bottom of the new thread page.