This is an overview of the site and its features for new users. It quickly covers navigation; mobile uploads; creating a channel; social features like favoriting, rating, sharing and commenting; YouTube blog: http://www.youtube.com/blog; Help Center: http://www.google.com/support/forum/p/youtube?hl=en; Community Guidelines: http://www.youtube.com/t/community_guidelines

Also, big thanks to LiveLavaLive, ShaneDawsonTV and LisaNova (in order of appearance) for the opening sequence. Their channels are:

http://www.youtube.com/livelavalive
http://www.youtube.com/ShaneDawsonTV
http://www.youtube.com/user/lisanova (less info)