If you are looking for resources to teach the Harry Potter books, then The LeakyPedia is a great place to start.
Presented as a wiki, the LeakyPedia has excellent information on Harry Potter and the Philosopher’s Stone, however the rest of the books and all of the films need additional information. I see this an an opportunity for students who are fans of the books and/or the films to submit something to the site. The style of articles for the wiki has already been laid out, so students would be able to easily follow the templates on the site.
There are also opportunities to add information about the Wizarding World of Harry Potter, biographical information about J.K Rowling and subjects such as Muggles, creatures, spells and more.
This could be an engaging task for students to complete some detailed writing for an authentic audience.
The people behind the wiki are the developers of the world renowned Leaky Cauldron website.