The “map”, or the organizational system used to decide where to shelve books, is called Library of Congress. This system is similar to the Dewey Decimal system you may have used in elementary or high school. It groups books and DVDs with similar themes into the same letter category, and then gives each book a unique number that is more specific about its topic.
For example, this book “Climate Change: what everyone needs to know” has a call number of:
RA 793 .R66 2018
RA stands for Public aspects of medicine
793 stands for Medical geography, climatology and meteorology
R66 stands for the author, Romm, Joseph
2018 stands for the year of publication
All the books are shelved alphabetically, and then numerically. When you find a book you’re interested in, write down the call number and then follow the letters and numbers until you find your book.
Here is a summary of the Library of Congress classifications. You can also go to the shelf and browse for interesting books on your topic
A – General works
B – Philosophy, Psychology, Religion
C - Auxiliary Sciences of History
D - World History and History of Europe, Asia, Africa, Australia, New Zealand
E – History of the Americas
F – History of the Americas
G – Geography, anthropology, recreation
H – Social Sciences
J – Political Science
K – Law
L – Education
M – Music and Books on Music
N – Fine Arts
P – Language and literature
Q – Science
R – Medicine
S – Agriculture
T – Technology
U – Military Science
Z – Bibliography, Library Science, Information Resources (General)
The libraries have different locations for different materials. DVDs are kept in different places than books; children’s books are in a different location than adult books; periodicals (magazines and journals) are in another location. And reference books (large books that provide an overview on a topic) are kept in another place. They will all have similar call numbers, except at the end of the call number, a location identifier will be there.
For example, if you’re looking for research material about moose, you can find it in a variety of places:
QL 737 .U55 .G57 – this is in the main collection
QL 737 .U55 .R54 JUV – This book is located in the Juvenile Books section (kids' books)
QL 737.U55 .M66 AV – This is a DVD
QL 751 .E61 REF 1987 – This is in the reference section
You can browse QL 737.U55 in any section and you will find something about moose. In the reference section you may have to go a bit broader, but there will be something relevant close to the numbers you were looking for.
Not sure how to find a book on the shelf? Feeling intimidated by all the letters and numbers in a call number? Don't worry, it's easier than you think. This video will give you the tools to find what you need.