As the new season approaches, however, we have been promised more of a look inside of the TARDIS, so, as with anything else, fanon will bend to canon in regards to the TARDIS and the Doctor unless specifically stated. If I say the pool water is blue and we find out it's pink, it becomes pink.
Anyway, on to the fun stuff. I'm going to have a list of "Canon" rooms introduced in the Doctor Who timeline, and then "Created" rooms that I invented in my own wee little brain. If you're a fan of the show and know of a room that I've missed (or a timeline error), please tell me.
(first seen in An Unearthly Child, visual update in Rose)
The "bridge" of the ship, which contains the console and much important TARDIS equipment, also the place of the front door and viewing screens.
(first seen in Edge of Destruction as 'sleeping area', updated to bedrooms and later seen [Romana's bedroom] in Full Circle, creation updates by me)
Bedrooms created within the TARDIS for companions. Fairly empty and easy to play around with. Visual update to include automatic furniture and TARDIS 'creation' of rooms at will.
(first seen in Logopolis, visual update in The Enemy Within)
Place of reflection and meditation, contains the Cloister Bell, which chimes whenever the TARDIS is in imminent disaster. Visual update makes it a large, open area that contains the Eye Of Harmony in an almost religious-type setting. There are bats in the belfry, literally. Thanks to ki2k and shaman_x for canonical repair!
(first seen in Edge of Destruction, visually updated by me)
Eatery, complete with a replicator-esque food creator. Visual update includes refrigerator, stove and couches.
(first mentioned in Edge of Destruction, first seen in Androids of Tara, visual update in A Christmas Invasion)
Large room amass of clothing which the Doctor has picked up throughout various travels. It is a bit like an overstuffed closet on top of a spiral staircase.
(first seen in Castrovalva, visually updated by me)
Pink-and-grey room of non-interference. All special distortions and psychic waves are blocked in this room, however if the door is opened then a psychic projection can seep through. It smells of roses, and even the Doctor is not quite sure why.
(first shown to Anne, later to Reinette)
Circular room with cushions that projects everything around the immediate vicinity of the TARDIS. Has a built-in stereo system that can be set to any radio station.
The Doctor's Bedroom
(first shown in this prompt, later further explored in this prompt)
Like a room of a small lord, with wood paneling and a large four-poster bed (that has yet to be 'broken in', despite how much of an Oncoming Shag the Doctor can be). Papers and books are stacked from floor to ceiling, and clocks line every wall and the fireplace. There is a tribute to the Menti Celesti near the bed.
(not yet shown, but will be soon)
(first shown to Aislinn, later to Reinette)
Five-story domed room like a small museum. Books are categorized and lined on long, school-library shelves. Hallways are dotted with marble statues and the occasional suit of armour. Bat-like creatures live near the top of the dome, and the TARDIS creates new floors in this room to accommodate new knowledge. There is an early-century Earth lift in the middle of the room, and it appears, despite the style, to be the newest piece of equipment in this room.
(first shown to Reinette)
Like an odd jumble of various human bathing and pool styles, this room was created by the TARDIS after the episode Paradise Towers in which Mel was nearly killed in her attempt to find a place to swim. The entire floor of the pool is made of Tereliptian metal (first seen in The Awakening) which is "squishy" and pliable and conducts heat.
Wind Machine Room
(first shown to Anne)
A large, empty room with a huge fan that creates anything from a soft breeze to a torrential gale wind by the push of a button. The walls and floor are hardwood, presumably to help with air flow.
This list will be in the Doctor's memories, and will expand and grow as I create 'canon' for my pup