For the videos, press the triangle in the center. Then, in the second window which comes up, you may want to to press the PAUSE button and let it buffer while you go pour yourself a drink or something (if it is not fully buffered when it starts, it may stop and skip a bit). Some people have fast enough internet that this is not a problem. When I view them, though, I have to pause it and wait a couple of minutes.

Music by Keven MacLeod (incompetech.com)