Some basic videos that everybody in technology world should know and learn:
Setup Domain Controller and know how to access your shared drives, setup user accounts, join domain, and use tools available to you.
(1)http://www.youtube.com/watch?v=QGfwfWcLFMw
(2)http://www.youtube.com/watch?v=PelA-_gT2qE
(3)http://www.youtube.com/watch?v=8hrhwzN15A4
(4)http://www.youtube.com/watch?v=2-7g_gA9NCg
(5) http://www.youtube.com/watch?v=T1AZgXqi2yQ
Know how to record your desktop so you can record and do training manuals for users.
http://www.youtube.com/watch?v=n9nAQg0B_Gk
Know your command line: