My thought on reading as an idle activity and learning: Since many engravings are mostly symbol/heiroglyphic based, what about engraving words alongside the engravings to further explain the background of the engraving in more detail?
Then again, my original point I meant to speak about, if we'll be having a writing skill, should we compliment it with a reading skill? Literacy could be a combination of the two and minimize troubles. I mean, considering the era of the game, I would have doubts that everyone could read or write (replacing said skills with symbols if lacking literacy skills; much like a young child). They understand symbolism of certain glyphs and interpret them (like what we're familiar with already in-game); even the most unskilled adventurer can tell what certain engravings and such mean, but if there's actual writing involved, they'll need to be literate to interpret it even clearer, as well as write it just as clearly. Since literacy would cover ground on the reading and writing aspects, then accompanied with the learning skill, it can really boost the learning speed of additional skills, including literacy itself (to a limit of course, as to not make a gamebreaker out of it). It can really help with the more noble skills like leadership and book keeping and so on without actually requiring to do the work to boost the skills. Think of it like reading math and accounting books, and then applying them later.
Low literacy skill = low quality books produced = dabbling skill learned by reading at most.
Legendary literacy skill = masterful - Artifact books = Master skill learned at most (provided skill level-equivalent literacy skill to understand it).
Of course, the skill level of the subject the dwarf writing it has to be just as well as what is to be written and read in order to give complete benefits. The writer has to know his craft and have a high enough literacy skill to translate it to their readers, and the readers need a high enough skill in literacy to understand what the heck the writer was talking about in the first place.
So, when producing:
Legendary skill + Legendary Literate = Masterful-Artifact skill book
Legendary skill + Dabbling literate = Dabbling skill book (or skillful, if working on averages. He knows what he means, but he can't quite get all the details down to the letter.)
Dabbling skill + legendary literate = Dabbling skill book (he writes eloquently about not much)
And as for reading:
Masterful Skill Book + dabbling literate = Dabbling skill (My brain hurts, I can't learn more than the first HOW-TO tutorial(s)/chapter(s))
Masterful skill book + masterful literate = Masterful skill (in due time, like bookkeepers; leave them to their books for a good season, and they should be up to snuff.)
Dabbling skill book + masterful literate = Dabbling skill (I understand it all, but that's all I can learn from it)
Dabbling skill book + dabbling literate = Dabbling skill (despite like-minded reading quality, he has a good idea of what he's reading; but that's all he'll understand anyway. Not much more detail beyond that)
Something like that. Or we can work on a system of averages.
Dabbling skill book + masterful literate = skilled skill
I dunno how the visibility of the educational value of a book can be seen from the cover ("don't judge a book by it's cover"?), but depending on the skill of the publisher and the materials, even a crappy educational or entertaining book can still fetch a good price, provided good materials used (or artificated) for production. Of course, this means papyrus, paper, and such will have to become products that can be used, with an off-chance that a printing press (Gutenberg-style) will have to be a new workshop (Call Urist Gutenberg).
EDIT:
I suppose educational quality can stack on top of it's production quality.
Masterful quality book (production/reproduction) + masterful skill book (literacy) = truly valuable book (very expensive)
Dabbling quality book + masterful skill book = very valuable (EDU picks up majority value here) (expensive)
Masterful quality book + dabbling skill book = decently priced book (It looks fancy. mostly decoration bonus) (Average or lower price)
dabbling quality book + dabbling skill book = Cheap book (looks crummy, and is not satisfying to read) (vendor trash price; or simply put, only worth trading if you need that extra ☼ for exchange).
In other words, brains and brawn + lots of literacy + and excellent publisher/bookcrafter + *the right materials = ☼☼☼
*BiblicalTales, the History of the World
Price: 325000☼
This is an educational tome. it's writing within is of highest quality. The theme of the tome is **World History. the tome is of masterful quality. the pages within is made of Cave Spider Silk papyrus, the writing within is in Dimple Dye, the cover is made of cow leather, it is adorned with a chain of red cave spider silk, embedded on the front cover is a cut sapphire, embedded on the back cover is an illustration of Urist Gutenburg, the author of the book. It menaces with spikes of gold.
**The tome teaches leadership and teaching, it is a fun read (Happy thoughts).
With necromancers:
DeathDwarf, A Necronomicon of Doom
Price: 666000☼
This is a powerful tome of spiritual ritual, it's writing within is of highest quality, the theme of the tome is Necromancy, the tome is of masterful quality. The pages within is made of cave wheat paper, the writing within is in dwarf blood, the cover is made of dwarf leather, it is adorned with a chain of green cave spider silk, embedded on the front is a cut ruby crystal. engraved on the front cover is a dwarf screaming. the back cover is adorned with chains of red cave spider silk. embedded on the back cover is an illustration of EnragedDepths the fire elemental and dwarves, the fire elemental is eating the dwarves. It menaces with spikes of pitchblende.
The tome teaches necromancy (obviously) and biting, it is an entertaining read (Happy thoughts).
EDIT EDIT:
Considering things, I think nobles can actually help refine fortresses quite well (improving social skills and speeding up education) if they also carry some literacy skill and produce some books themselves (or bring some with them). Of course, others like the dungeon keeper would probably teach/write about how to get away with wearing only a cape while drunk out of your mind. A really valuable and actually helpful noble could be Scholar. They generally come with high literacy and teaching skills, come with some books on hand, and their requirements allow for classrooms to be made. Think of it like a dwarven college... or a regular modern campus really. I can imagine a dwarven campus isn't all too different from today's college campuses anyway. Only thing missing here is magma and tons of cats.