I've created a few new races, classes, and magic types for this campaign, including the wolfwere (an animal able to turn into a man, rather than the other way around), the Skinscribe (a mage who uses his tattooed skin as his spellbook), the Dwarven Sapper (who builds and destroys), and the White Mage (which uses the cleric spells, but the mage spell progression, including the ability to research new spells); however, there is one particular class of magic that has had tremendous impact on the world of Mor-Thir, especially within Mareten: Librarians.
Long ago, in times not forgotten, lived a man named Quentin Querulous. While scrolls and books of ancient knowledge were present even then, they were stored is jumbled heaps and stacked on creaking shelves. Mages kept their own books, and few outsiders were allowed to read them - if they even could. It was unheard of to own a large collections of books, simply because of the space required - many books could not sit in the same room, let alone the same shelf, as other books, simply because of the amount of magic contained within. The more books one owned, the more likely stray magic would begin arcing between them, killing anyone nearby and usually reducing the area to a glowing crater.
Quentin owned a few mundane books, but little else; he was quite poor. However, he chanced to find a magical book - a discarded spellbook, with only a simple spell within. Elated, he brought the book home, and set it reverently upon a shelf of its own. the next day, he found it had scooted forward; he replaced it, only to find it nearly falling off the shelf the next day. Intrigued, he began to study the movement of the book, and found that for whatever reason, it was attracted to another book of his. When he placed the two side-by-side, they remained solidly in place. Surprised by his discovery, Quentin sought other books - discarded spellbooks, tattered scrolls, and any number of mundane books, for as he found, even a boring book on the history of the juniper tree had a bit of magic in it - how else can it put students to sleep so quickly?
As his book collection grew, his experiments became more serious; more and more powerful magic found its way onto his shelves, and was calmed by the surrounding books. All of Quentin's savings went towards purchasing magical books, and any time not spent experimenting was spent begging books from mages, to borrow or to keep. Eventually, a few nearby mages began to wonder what Quentin - not a mage himself - would want with so many magical books, and paid him a visit. Inside his home, they were terrified to see so many magical tomes stacked together, lining walls from ceiling to floor! That much magic could level an entire village! And yet... it was stable. Recovering from their shock, they realized that somehow, this man had devised a way to safely store magical material.
At once, they brought him to their enormous storehouse of books; within a few short hours, Quentin had reduced nearly an acre of chained-down books to two neat rows of tall shelves. The books slid smoothly out, and could be replaced without the slightest effort. The mages were astounded. The next day, Quentin awoke a very rich man - and not just because of a purse filled with gold. Quentin had been placed in charge of the libraries of several nearby mages. As time went on, and his benefactors grew their collections, Quentin drew in others of like mind to assist him, eventually beginning a college of his own: a Librarian college.
Handling all those books rubbed off on Quentin; his magical abilities grew into a new kind of magic. Not magic stored in a book, but magic stored in all books. He taught his assistants, and they taught theirs; today, there are librarians all over Mareten, with huge rooms full of books, dedicated to organizing and collecting. Their libraries are free to use, provided you have a library card.
While the original librarians are numerous, there are two other librarians of note: the Gnomish librarian, and the Elven Polydoctorate.
The Gnomes, often silly, have expanded libraries to include not just books, but the spells they contain; enchantments and illusions come free of charge, and storytelling day is the most well-attended event each week.
On the other hand, the Elven Polydoctorates take studying to entirely new levels. As a full Librarian, a full Cleric, and a half Mage, polydoctorates are likely the most powerful spellcasters in all Mareten. Their grasp of spellcasting is immense, and their personal libraries are incredible. Only the long-lived Elves could amass such knowledge.
Quentin would be proud.
Oh, and before I forget... Quentin was often heard conversing with his books; a few of his assistants swore that sometimes, just sometimes... they heard the book talking back.