Remember the day of discussion forums and discussion walls? Google is trying to popularize them again through an innovative feature called Google Moderator.
Google Moderator allows you to post a question (also known as a series) about a topic that you are interested in discussing. This Google feature allows you to open it up for other users to submit ideas, suggestions, and questions about your question (also known as submissions). Participants can view other discussions and even "vote."
If you want to break your "series" into an easier to manage format, you may want to consider creating a topic (aka another way to break up your series). For example, if you create a series called "Professional Athletes," your topics could be called "NFL," "MLB," and "NBA."
Watch out though! At this point anyone can come to the site and post a submission to your series. This may be a great way to connect with users beyond your classroom. Try it out and see the possibilities.