You'll need to scroll down the menu to find the links which will allow you to download the Sound section of the manual. The Southeastern Michigan Math-Science Learning Coalition offers over 200 lessons plans, organized by grade level. Included within the site are sample teacher activities that could be used as classroom demonstrations and sample teacher investigations that could be used as classroom labs. This section of the Physics Classroom contains a tutorial on sound which consists of 5 lessons with 19 sublessons. Contents cover the nature of a sound wave, sound properties and their perception, behavior of sound waves, resonance and standing waves, and musical instruments.
Lessons contain problems for students to check their knowledge and animated GIFs to teach concepts.
There are at least three science experiments suitable for the home or classroom on sound at this site. The three that were on the site when it was reviewed are intended for young children and address the principles of sound, how sound waves are formed, and how to make a homemade hearing aid. This database has at least 10 lesson plans on sound in their section on Waves, Sound, and Optics. A Unit and Lesson Plans 30 activities tied to learning objectives for intermediate strudents. Sound is Energy This ThinkQuest Junior site looks at sound within the context of an orchestra.