The art collection is split between the Honnold and the Mudd side of Honnold/Mudd Library. The main call numbers for art books are N-NX (located on Mudd 1) and TR (located on Honnold 1). Books in those areas are divided by medium (painting, drawing, photography, tc.) and then by subject and artist.
In general, it is easier to locate something specific by searching online first, but for those who like to browse, here is a list of call numbers that pertain to art. Remember: About 1/2 of all the art books are oversized (aka FOLIO) and are on a different set of shelves
AM -- Museum Studies
E 75 – E 99 -- Indians of North America (traditional arts and crafts of Native North Americans)
GT -- Body Art, Tattoos, Graffiti
N -- Visual Arts (includes a lot of contemporary art that doesn't fit in traditional categories)