just use the console , click on the book case and type "unlock"
]by the nine! i dont know why everybody is always moaning about it when you can just pop up the console , ow and my apologies if you play on xbox/ps3 because then you are screwed

I play on both the PC and PS3. My arm is hurting badly from Skyrim on PC, so I'm out of commission when it comes to PC gaming. Same thing happened with Morrowind. My body is weak... I was clicking like crazy from 4 PM to the minute The Boondocks came on on advlt Swim. Or was that Deadman Wonderland. I was playing too long, and now I suffer.
Never use the mod that gives you a part of Elsweyr and do the quests at a low level. Arm pain may happen... I tgm'd that stuff... Why does it seem like every PC version of a TES game makes an arm or two hurt because I play them too much when I first get them? I do this with every new game or version of a game I wanted. Console games don't kill my arms as much as PC ones do. I use a laptop and don't use an external mouse, so yeah...