using CMS.Polls;

...

        // Create new poll info

        PollInfo pollObj = new PollInfo();

        // Set the fields

        pollObj.PollCodeName = "testingSitePoll";

        pollObj.PollDisplayName = "Testing site poll";

        pollObj.PollTitle = "Your free time";

        pollObj.PollQuestion = "What do you do in your free time?";

        pollObj.PollResponseMessage = "Thank you for your vote.";

        pollObj.PollAllowMultipleAnswers = false;

        pollObj.PollAccess = SecurityAccessEnum.AllUsers;

        pollObj.PollOpenFrom = DateTime.Now;

        pollObj.PollOpenTo = DateTime.Now.AddMonths(1);

        // Save the object

        PollInfoProvider.SetPollInfo(pollObj);

        // Add poll to current site

        PollInfoProvider.AddPollToSite(pollObj.PollID, CMSContext.CurrentSiteID);