Not sure how many on here are familiar with the world of YouTube vloggers so here goes:
People create accounts and post videos to their page/"youtube channel", sometimes daily or weekly, whatever.
You can sign into Youtube and "subscribe" to these people, so when you go to youtube.com all your favorites appear.
Among these people are the Vlog Brothers. 2 brothers who started posting videos to each other and now genereate millions of views on various YouTube channels.
The Bros.: John Green, a fantastic, amazing, wonderful author (fiction) and Hank Green a musician and both of them have an amazing commitment to science, history and reason.
Anyway, in an effort to help educate the public (including a very young viewer base) they created these informative channels, one of which is the SciShow. Go check it out: http://www.youtube.com/user/scishow
For some it will be elementary and for others it will be informative, but they are always entertaining.