Northwest ISD is not responsible for content on external sites or servers
When you use any pictures, music, videos, etc. you have to find copyright free resources.
http://incompetech.com/m/c/royalty-free/ (music)
http://pics.tech4learning.com/
http://www.geekphilosopher.com/MainPage/photos.htm
You always have to give credit to the pictures, music, videos, etc. you use.
Here are 2 examples:
Ocean image by Coach Moore from http://www.freephotosbank.com/
Music: It's Not Over by Chris Daughtry