From the Apple start page:

Need to write a research paper for a summer course? Then you’ll want to pay a visit to the Florida Community College at Jacksonville and sign up for English Composition II. The 24-unit video course provides a comprehensive resource for writing academic essays. And you can also learn about technical writing, writing for business, and literary analysis, as well. It’s another fine course available on iTunes U.
This course loads in iTunes when you click the link. It is a complete set of lectures in video podcast format, so it is very large. I haven’t had time to review it yet as it has only just started downloading but the lecture list looks comprehensive and in-depth.
Don’t click on this unless you have lots of space on your hard-drive and a fast Broadband connection.