This library and most public and school libraries in the country use the Dewey Decimal Classification System for their non-fiction books. There has been a move by some in the library world to drop the system. I know that some might find the string of numbers confusing, but it is actually one of the better ways to classify books out there, especially when it comes to finding a particular book or a particular subject.
Here is a breakdown of the basic Dewey list:
The Ten Main Classes
000 Computer science, information & general works
100 Philosophy & psychology
300 Social sciences
700 Arts & recreation
900 History & geography
Over the next couple of weeks I will be writing on how I find the Dewey Decimal System useful, starting with the 000s all the way to the 900s (and then back to biographies, which, while 92s, are shelved separately). For a really in-depth treatment of Dewey on a blog, check out 025.431 The Dewey Blog (025.431 is the Dewey Decimal Subject for, you guessed it, the Dewey Decimal Classification).