Texas Education Agency
Texas Gateway: Oscillatory Motion and Waves: Conceptual Questions
This is a list of 18 questions covering the major concepts in Chapter 16: Oscillatory Motion and Waves from the AP Physics online text.
Texas Education Agency
Texas Gateway: Simple Harmonic Motion: A Special Periodic Motion
By the end of this section, you will be able to describe a simple harmonic oscillator and relate physical characteristics of a vibrating system to aspects of simple harmonic motion and any resulting waves.
Wikimedia
Wikipedia: Simple Harmonic Motion
Wikipedia offers great information on simple harmonic motion, including an image, formulas, and hyperlinked terms.