Here is a an excellent review of free multimedia resources for use by teachers and students http://classroom-aid.com/educational-resources/multimedia-resources/
Next Vista http://www.nextvista.org/ NextVista provides an an excellent collection of free videos for teachers and students. These free videos for learners are made by students or teachers around the world. Here is an online community willing to share educational videos . All videos are screened for inappropriate and inaccurate content.