A seven-year test of libraries in .43.03 comes to the conclusion ... probably not worth it with rookies?
Four randomly-chosen dwarfs with no prior academic skills produced seven books in seven years. Skill advancement was abysmal (and that's putting it nicely) - massive round-the-clock pondering/discussing gave about one skill level per two years, and only for two of them: one gained a few levels in tracker and wrote a book about animal foraging, the other gained three levels of critical thinking but never wrote anything. Another dwarf made a breakthrough in archeology and wrote a book about that.
The other five books were random garbage - tourist's guide of the fort, private memoirs. I also turned eight soldiers into scholars, to see whether they'd make a military academy or whether their massive teacher/student skills had any benefit. No such luck, they produced one commentary on the archeology book in two years, that was it. 46 dwarf-years of research, eight written objects, of which three of academic interest. I guess you'll have to embark with proper scholars or attract them as guests, training on the job looks pointless. If the willingness to write anything at all depends on the writer skill, you'll really have to spend embark points on it - you definitely won't get notable skill (or an appreciable number of books) when "dabbling" basically means one book per ten years per dwarf
It didn't help that the dwarven civ has no real base - king and barons, liaison and caravan all exist, but dwarf isn't a playable adventurer type (even after retiring the fort) and the caravan never brought finished books.