As far as learning goes most of it seems self contained from cultural packs bought by dukes in the EP store.
Schools for the most part are just research centers where a consolidated group of people are advancing technology through mass research which is then shared to everyone in the community.
Beyond that books seem to just be common circulated texts with other rare books found through exploration which can further advance your skills to apprentice level or further if you find lost books or create the research yourself.
Or that you can simply teach someone what you know through instruction without texts in an apprentice/master role.
Or through observing people do things you can learn.
Or practicing skills.
So for the most part teaching needs no special purchasable packs unless they decide to sell specific texts for non duke players. Everything else is self contained within the game.