This is an idea that I have used in our home school often through the years. *I was just thinking I do a lot of online extras BUT the internet is a tool in our home and home school. I always recommend monitoring it closely. Our computers and laptops are in public areas and I continue limiting and checking how much our daughters use them AND what they are doing on them. That is a parental responsibility in this day and age. *I do trust our children often, but I don't trust their friends usually - parents have different rules, so it is important to keep an eye on even our trusted children. I was reminded of that recently.
BUT using Youtube in our home school has been a valuable tool. I am always looking for tips and links to illustrate what we are learning about.... I often check out Youtube for a video to make a lesson come to life. It works for checking out: animal habitats for science, current news stories, art or paper play techniques, math extras - Doodling in Math Class, anyone? (We love her series on Sprials, Fibonacci and Being a Plant), historical videos (Ancients Behaving Badly - Genghis Khan- there are many other videos, too) and much more.
Here is a link to Using Youtube in Your Home School for even more ideas.
I think the key is to make home schooling work in your home. If you are comfortable with Youtube, it is just one more tool to use!