This video from the Harley Street Medical Center is a great video that covers methods to identify a sleep disorder. This is a perfect video for use in a presentation or class due to the lack of voice over. This will give the student/presenter a clean slate to create audio. You could even mute the video and create your own audio track timed to the video.
AnswersTV.com discusses the prevalence of sleep disorders, what sleep disorders exist, and what symptoms make a sleep disorder. Also, they give an overview of different kinds of sleep disorders. What do sleep analysts look for when doing a sleep study? Describe the following: dyssomnia, parasomnia, insomnia, hypersomnia, and narcolepsy.