"There is a wealth of video content available online that can help the teaching and learning process, but some of the main issues of using online content within the classroom include inappropriate advertising, inappropriate recommendations, and the dreaded school firewall or slow internet connection. Yet, gaining access to such video content can really help to explain certain concepts, with opportunities to include footage, clips or teaching points in the lesson."
This is a list of sites compiled by librarians to safe use internet sites. A great reference for school administrators, techies and teachers. It is a maintained directory of sorts and you can submit safe sites.