Had an idea last night for Skyrim as the skill book achievement is one of the last that I require. I came up with the idea of a book thief, mixt between a thief and an illusionist who is passioned by books (they are really awesome to read ) and who goes out of his way to get books. I have been reading on the lore wiki for an hour now and haven't found an answer to my question: which race would be more fitted for a book thief? What race crave lore or infos more than any other and would not mind getting his hands dirty to get books?

Zul

Its not so much race as personality.
An individual of any race can be cowardly or strong or stupid or learned.

I think a Bosmer might suit your roleplay.
They have an eagerness about them, but as I said its more about personality than race really.
Youd have to invent a background that fits your roleplay.

Maybe youre a Bosmer that has come to Skyrim to find and preserve knowledge before it is forever lost in the war?
Maybe you work for a clan or family or sect that likes libraries.

If ya put ya mind into it, any race would do.

I actually made the character you're describing before. She went around trying to collect every unique book in Cyrodiil to make some type of crazy library. She was a Bosmer (and for the record, she was ultimately unsuccessful.)

However, as has been stated, any race could easily fill that role.

Orc:

Shunned by his clan mates for wishing to gain knowledge and experience from the written word rather than the ashen glow of the forge or the steely, bloody heart of battle and conflict, he left his Stronghold, forever a shame to his father and brothers and sisters in arms, and traded the Code of Malacath for the pursuit of the quest in ink and the paper-bound world. Initially he traveled north to Solitude, seeking out the famed Bards College. Indeed the place had always been in his mind ever since he caught a whiff of song on the air, sung by a wandering skald. To his chagrin though, he was met with blank stares upon entering the front doors of the college, as the dean of history saw not a scholar but a brute and a thug. Thus after he finally convinced the headmaster of his intentions he was met with only lukewarm reception, and immediately sent on a quest into an old Nordic barrow to retrieve a literary relic. Verily these bards at the college could not see past his Orcish exterior and treated him no differently than any contractually bound mercenary; a simple errand boy and warrior which was no different than how he was expected to act around his estranged brothers back at the Stronghold. Disillusioned, he sought out the general store in Solitude, but when he asked for a stock listing of books, the proprietor sternly informed him that if he wanted to wipe his ass it wouldn't be with any of her merchandise. Sore, sick, and utterly tired of the stereotype he was born into, he could feel the orcish rage building inside of him for the first time in his life. If the world didn't want to help him, he'd help himself. Indeed he didn't want to read and study for the sake of other people. He wanted it for himself, so that night he took his life further into his own hands than he had ever done before. The door to Viarmo's study in the Bards College wasn't a big issue nor was the sneaking required to get to it and silently root through the contents of the headmaster's private collection. These actions were not unknown to him. In the Stronghold all orc children stole what wasn't provided to them by their mothers. That was how life worked, and if you were caught you weren't punished for the thievery as much as you were for being clumsy enough to get caught in the first place. Yes, this life was right for him. He stole a great number of books that night along with the Giraud Gemane's best quill. He planned not only on reading these volumes to death but also making his own notes so that he may gain the fullest understanding he could. A few minutes later he was out the door back into the cold, damp Solitude night with only the Aurora Borealis and the Gods themselves, possibly even Malacath bearing witness to his silent entry into the general store to take through legerdemain what should have been offered to him through courtesy, and just before he left, he spotted a finely woven doublet which just to satisfy that great literary term known as irony, he then wiped his ass with. His new life as a scholar and taker had begun.

Khajiit would work as well. My thief likes booze, shiny things, and books. Obsessively. I blame the skooma.

Khajiit - They are the thieves with a purpose. Of course, they don't need books.

Did you just write that?? Maaan.

A Breton of course, they are simply better at everything then anyone else.