For a time, the TARDIS control room contained a library, (TV: Doctor Who, COMIC: Endgame, AUDIO: Storm Warning) but, even during that time, the Doctor had a separate library as well. (PROSE: War of the Daleks, AUDIO: The Man Who Wasn't There)
The Eleventh Doctor's TARDIS library was at least four floors high, with detailed architecture and vast amounts of bookshelves on each floor. The library was not modern in appearance but quite old-fashioned, with dark, walnut wood furnishings reminiscent of the styles of both medieval and victorian architecture. It contained several desks and lampshades, and the shelves appeared neatly organised and tidy. At least one shelving unit contained locked drawers. (TV: Journey to the Centre of the TARDIS)
Ian Chesterton and Barbara Wright first learnt of the library when the TARDIS arrived in Tyre. Barbara was somewhat put out that neither the First Doctor or Susan had told them about it. Through consulting his books, the Doctor tentatively concluded that Ian had ultimately inspired Aeneas. (AUDIO: The Phoenicians) Later taking a tour of the TARDIS, the library was Ian's last stop before he returned to the console room. (COMIC: The Path of Skulls)
When the TARDIS landed in Ekaterinburg shortly before the Russian Civil War, Susan was meditating within the library. (AUDIO: Last of the Romanovs) She later consulted its books to discover the fate of the Library of Alexandria. (AUDIO: The Library of Alexandria)
While the Fourth Doctor was not speaking with Leela after an argument, she found her way to the library, marking the walls along the hall. Leela decided to study a book of fairy tales to learn more about potential threats on Earth. When the Doctor discovered her, much to his surprise, she was reading "Jack and the Beanstalk" out loud from the book. He first checked the boot cupboard, the sculleries, both swimming pools and the lagoon. (AUDIO: White Ghosts)
Early in his adventures with the Eighth Doctor, Fitz Kreiner went to research something deep in the stacks of the TARDIS library. He found an old woman sleeping there, covered in cobwebs and surrounded by books about British birds. (PROSE: Mad Dogs and Englishmen)
When the Eighth Doctor, Lucie Miller, Susan, and Alex Campbell were attacked by a Blitzen fish during Christmas dinner inside the TARDIS, the library was among the rooms they were chased through. While there, they consulted Gauntlet's Bestiary of the Fourth Universe. (AUDIO: Relative Dimensions)
The library's books included Brave New World, (PROSE: The Wheel of Ice) Jane's Spaceships, (PROSE: War of the Daleks) Jane's Spacecraft of the Universe, Aladdin: The Script, Parachuting, A-Z of Planets, VNR The Collection, Timeview, The Time Machine, Collected Works of Beatrix Potter, The Baker's Dozen, Corpse, Vegetarian Cook, Vanity Fair, Freeman: Editorial Decision, The Early Years, a book on aerobics, (PROSE: The Deal) Every Gallifreyan Child's Pop-Up Book of Nasty Creatures From Other Dimensions, (PROSE: All-Consuming Fire) Robinson Crusoe, (PROSE: Heart of TARDIS) Wisden Almanack, (PROSE: Fear of the Dark) War and Peace, (PROSE: The Deal, AUDIO: Terror Firma) Baedeker's Galactic Guide, Bajazet Magna to Bali, (PROSE: Cat's Cradle: Time's Crucible) The Wonderful Wizard of Oz, The I-Spy Book of British Birds, Can you forgive her?, You Only Live Twice, Frankenstein, (AUDIO: Storm Warning, Zagreus) Pieter Montmarche: A Diary of Discovery, The Little Book of Starships, (AUDIO: The Man Who Wasn't There), the only signed copy of The Quarry in the universe (PROSE: Keeping up with the Joneses) and a signed copy of Reminiscences of the Peculiar by George Litefoot. (AUDIO: The Carrionite Curse)
Some of the library's history books included A History of the Varaxil Hegemony, (AUDIO: The Witch from the Well) Histories of the Dalek Imperium, (PROSE: Keeping up with the Joneses) The History of the Time War, (TV: Journey to the Centre of the TARDIS) A Brief History of Time, (PROSE: Fear of the Dark) and Fashion Through the Ages. (PROSE: The Deal)
Books kept in the library which were of personal significance to the Doctor included a signed copy of The Murder of Roger Ackroyd gifted to him by Gemma and Samson Griffin (AUDIO: Terror Firma, Terror Firma) and his Five Hundred Year Diary. (PROSE: The Deal, AUDIO: The Young Lions)
The contents of the library were not limited to books. It also contained a stack of 45 singles and EPs by Billy Fury, Adam Faith and the Beatles, (PROSE: Cat's Cradle: Time's Crucible) the sentient liquid Encyclopedia Gallifreya, (TV: Journey to the Centre of the TARDIS; PROSE: Citation Needed) and diskettes containing the complete works of the 21st century environmentalists. (PROSE: The Dimension Riders)
Unknown to the Doctor, the library contained books documenting the Doctor’s own adventures, which had been written by the TARDIS itself. The TARDIS admitted the records were not completely reliable, as it had sometimes altered details to improve the narratives. (PROSE: The Library of Time)
Behind the scenes
The incomplete television story Lost in the Dark Dimension would have featured the TARDIS library for a significant portion of the story. Set in an alternate timeline where the Fourth Doctor never regenerated and the TARDIS was mostly destroyed, the library would have been the last fragment of the ship remaining, camouflaged as a small church.
For some of the shots of the Eleventh Doctor's TARDIS library, Cardiff Castle's library was used. This vast library was built on the site of an old medieval hall during the 1800s, giving it a mixture of design influences from different periods of time.