High School Web Design is a site that has free lesson plans and resources for teaching a high school class on web design (hence the name of the site).
The site has lesson plans and project ideas, PowerPoint presentations, links, and an example course schedule. The site has a nice set up that is easy to navigate the information is formated well.
I would suggest that any high school web design teacher take a look at this resource. I'm sure you will find it worthwhile.
(It would also work as a review for students or teachers.)