A web quest is a teacher-focused web assignment for students to explore a specific topic. Although this site is aimed at middle schoolers, it looks to be a very useful visual and aural tool for any age. Here you will find the history of music from the Medieval times to the 20th Century. If for no other reason, visit this site for the quotations from various people throughout the ages on each topic. Although this site will ask you to register for a free membership, you still have access to a wide ranging database of musical information on instruments, styles, musical periods, contemporary topics, etc.
Most pages also come with related web links and other additional resources.
They have accumulated a wide range of useful resource pages for you to select from. This is also a great starting point for a detailed search. Classical Net - A soruce for over 4200 files and over 2500 links to other Classical music web sites. Find information on everything from suggested recordings to Composer's works and data. A VERY informative site.