Wow, what a fantastic time to share, enjoy.
I think most of the best ideas have been given - but just to agree with all of the above; be proactive and calm the curiosity, educate, put emphasis on safety and why, post easy and fun rules; get them involved if they want to help daddy, even encourage them; but what if.... where are your safety glasses? why are you wearing those slippers in the shop, etc. etc. lol; the red light is on, what does that mean?; personally I would provide some level of entry control when you are not in the shop but that depends on you and your family, could be locks, tool power, lights, etc. Re the red light, in my shop, my wife will not enter if she hears a power tool running for fear she distracts me at the wrong moment, she has suggested a red light many times.