I would have said lazy mom's guide but my husband doesn't like when I call myself lazy so I won't.
I used to do a craft, science experiment, and nature lesson every week with my children. That was before I had five children with the majority under age 5. My 11 year old started looking through our craft books a few years ago so I put him in charge.
He finds a craft in a book or makes up his own and comes to me for approval. He gets everything ready and then does the craft with his younger siblings.
I stay within earshot so I can tell the 7 year old boy to settle down or stop bugging his sisters, etc. Then when they are finished they clean up. Simple and easy for me.
And the younger ones learn to listen to their older brother and he learns how to teach and lead others. Works well for all of us.
Now if I can get one of the older ones to set up some science experiments...