YouTube is pretty hit and miss (but mostly miss) for specific educational clips for your students. For an alternative, try BrainPop and BrainPop Jr. for short, specific, age-appropriate, fun and educational videos to kick off a new topic or reinforce lessons and learning.
This site is a big hit with students for an excellent balance of humour and learning and a sure hit for teachers with its excellent content. I love how you can search the videos by standand, subject and grade too! The IPad app is also used by my two primary kids too! The Game Up section is my next area to explore!
ict4kids.ca 
Have you ever thought about writing an e-book or guest authoring on other sites?
I have a blog based upon on the same subjects you discuss and would love to have you
share some stories/information. I know my viewers would value your work.
If you are even remotely interested, feel free to send me
an email.
I will definitely consider your offer. Thanks for the message.