Last year's class, Growing in a Hoophouse, brought in a standing room only crowd, and this year it seems like it will be no less a popular topic. Lessons learned from that first experiment inspired many, and with good cause. Fresh garden vegetables not trucked long distances can be hard to come by in the winter months (although there are some new farms offering tasty green treats throughout the season), and growing your own is a good solution. As most gardeners know, a little bit of growing room can give a whole lot of harvest. (Imagine how delighted folks will be with a big bunch of homegrown kale for a present come December!)
Quite possibly more information than a homegrower might want, this MSU page detailing hoophouse construction offers invaluable information in text, video, and photos. The associated blog also offers notes from a gardener experimenting with her own hoophouse construction and harvesting. And another associated blog offers notes from the farmer working in the hoophouse! Both are great reading.
And don't forget Elliott Coleman's classics - Four Season Harvest and The Winter Harvest Handbook - for hoophouse plans, diagrams, plant lists, and planting schedules.