Frame guide
Known as a field guide in the US, this shows the different camera frame sizes. US animators plot out their camera moves on the field guide, which is basically a graph, and the camera operators follow their exact instructions. Japanese animators use their frame guides to determine the size of the camera at positions where it changes but use a large sheet of paper with the exact frame sizes and locations to plot difficult camera moves.

Desk lamp
As animation studios tend to be dark (and dingy) the desk lamp is very necessary. Candles tend to get messy wax on the drawings and can ignite them when the animator passes out at his desk from exhaustion and knocks them over. Most lamps are the old incandescent bulb type.
One animator I knew had a red light bulb he would screw into his lamp about 30 minutes before he would go home. "The roads are dark and looking at this red light helps me see further into the infrared spectrum." I suppose that he didn't ever figure out that not only was his night vision not infrared but that it was also destroyed the first time he looked at somebody's headlights.

Light box
Also called a trace box. Basically a box holding a fluorescent light fixture that shines up through a panel of frosted glass or milky-white plastic, the light box allows the artist to easily trace images on a sheet of paper below the one he is working on. Depending on the lights that are in the box the animator can normally see through 5 or 6 sheets.

Stopwatch
Used by key animators and directors to time out the scenes. Normally these are just normal stopwatches but some people use 24 frames per second or 30 fps watches to time film or video down to the frame. (If anybody knows of a handheld digital stopwatch that can do normal time and 24 and 30 fps the Japanese animation industry will be your friend forever if you tell us where to get them.)

Layout paper
The same size as standard animation paper, the layout paper has the TV frame and camera sights printed on it so that the animators can set up the scene.

Correction Paper
Thin yellow paper used by the animation supervisor and other checkers to make corrections on drawings without modifying the original. The yellow paper is much easier to see so the assistant doing the scene knows there are corrections to work from.

Time sheets
These are B4 sized sheets of paper that define the exact timing of all the animated elements in a scene for the camera operator or compositor.

Pencil Sharpener
Used to sharpen wooden pencils and chopsticks to stab the production assistants when they keep harassing you about the schedule.

Pencil sharpener

Clips

Used to hold stacks of paper together. (Ooh.) The ones below are used to bind settei, storyboards, scripts and time sheets. Animators also use various types of clips to hold the animation scenes they are drawing together so that the sheets will not slip while they are working on the inbetweens.

Clips

Scissors

Pointy, cutty things. It is advisable not to run when holding these pointed towards your face.

Scissors

Reference Material
No studio would be complete without bookcases full of encyclopedias, photo books, magazines and other books used for reference purposes. When you need to draw the Himalayas it is difficult to do so from past life memories and it's a lot easier to look up. Computers and video tapes and other sources of information are usually around as well.
Some studios keep all the old setteis, storyboards, key drawings, backgrounds and some even cels for reference. If you ever see a group of people videotaping each other writhing on the ground in a parking lot at 3 a.m. it's a good chance they're animators trying to work out a difficult scene.