This website has a bunch of different music vocab and history charts for the classroom. A good project for middle and high school students might be to have them design their own posters for the classroom using the knowledge they've gained in class.
Classics for Kids - a wonderful site with bios on on a long list of composers, great podcasts of audio stories of composers, music of the composers, games, and more! Parent/Teacher lesson plans as well.
Lunch with the Composers is a great way to introduce your kids to classical music. The posts go up on Sunday afternoon - each week there is a new piece of music and information about the composer with a video link included.