Yes this is the one I'd probably recommend. They may already have an html5 course. There are also wiki sites like wikispaces.com or you can use wordpress.com or there are sites like instructables.com

For what it's worth, here's my course on web development: http://internetdev.usu.edu/notes We just cover the basics of HTML and CSS, and then jump into using a content management system (drupal). I hosted students' drupal sites myself, but there is also this free drupal hosting site: http://drupalgardens.com/ For the basic HTML/CSS part, I tried out http://kodingen.com/ to let students do everything in the browser since the computers are locked down here. It has some issues, but worked okay.