Like most academic libraries in the United States, Booth Library organizes most of its collections according to the Library of Congress (LC) Classification System. Within this system, items are organized by broad subject area and given a unique call number, which you'll find on labels on the item's spine or front cover. This means materials on the same subject tend to be shelved in the same area. The first letter or letters on the spine label represent the subject area that the item falls into. Here's a short guide to what the different letters stand for.
For a more detailed breakdown, see the Library of Congress website.
For specific locations, see the Booth Library map, or use Map It! to locate a specific call number. Items in the Book Stacks are shelved as follows:
Items with call numbers beginning with...
A - H: 3000 level South (3rd floor)
J - L: 2000 level South (2nd floor)
M - N: 4000 level (4th floor)
P - PQ: 1000 level North (1st floor)
PR - Z: 1000 level South (1st floor)