I've been following the MacAdmins Conference on YouTube for a few years and many of their panels are just excellent. Even if you don't use any products from Apple, many of their topics are things that any systems administrator might need to learn, like networking, documentation, and project management.
I have recommended one of their videos many times. It does a great job of explaining the physics underneith wifi and I think that really helps people appreciate just how complex it all is. It is also very helpful for building an understanding of what issues you may come across and how to correct them.