Here are some links to Khan Academy and Youtube videos:
https://www.khanacademy.org/science/physics/oscillatory-motion
http://www.youtube.com/watch?v=wb0qpWTkMJQ&edufilter=E4DB5UeAo7DC2VhYbnQDlw
There's also DrPhysicsA on Youtube. Lots of people tell me he's great!
https://www.youtube.com/watch?v=DVtyRt0CSSw&list=PL5D99A319E129A5B7
