My little sister got this:
https://www.amazon.co.uk/dp/B00KVPK4QO/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
As a prize for something at school. shes 9 and was able to get started pretty well.
Its surprisingly excellent and covers a lot of topics on how CPUs work and computers are made, to networking to programming itself.
Good enough to get some adults started i'd say.
Everything is easier the younger your learn it, programming I think is an extremely valuable way of thinking as well as a vital skill even if you don't become a programmer. We have an issue today of everyone being expert users but nobody having a clue how anything actually works.