Anthropology

Reference works are a great way to get an introduction to a subject.

Specific call numbers for books are found in the online catalog, but when browsing the shelves, it helps to know something about them. 

The broad topics indicated by the first letter of the "call number" are often broken down into subtopics with a second letter, and are then refined in much greater detail with the addition of numbers. A full listing of Library of Congress call numbers can be found here: http://www.loc.gov/catdir/cpso/lcco/

The digits in these call numbers are read as counting numbers, not as decimals as in the Dewey Decimal system. This means that DL 1175 is found between DL 1174 and DL 1179, well after DL 117 or DL 118.

This arrangement of books by subject matter makes shelf-browsing convenient. If you find a useful book, the books nearby on the shelf are likely to be closely related in topic.