Tarot is more like reading a book than looking through a window. Again, the deck simply a vehicle through which intuition can act.
It is a very good idea to examine a deck before handing it over to your child. There are some really scary Tarots, and some that seem downright malevolent.
I feel the best way to teach Tarot is to allow the free flow of imagination. Give children a deck. Take a couple of cards a day, and let them tell you what the symbols on the cards mean. Write this down in their Book of Shadows if they aren’t old enough to write yet. Continue doing this until the deck you have examined all the cards. Then start from the beginning again, and compare the current interpretation with the original one. Let the kids make corrections and amendments in their interpretations.
After doing this several times, the decks’ owners will have a firm grasp of the meaning of that deck, to them. This is a lot more useful than learning someone else’s opinions of the cards.
The best spread to start with is the three card spread, past, present and future. Past is “what happened," present is “what is happening," future is what may happen.
The concept of reversed is simply opposite. Discourage value judgments such as “good”, “bad”, etc. You never really know how something is going to affect you until you walk around the next curve of the spiral.