Library Science (also called Library and Information Science) involves cataloging information and understanding how to categorize large amounts of information.  In a world where there is a huge oversupply of information, understanding how to categorize and organize it is critical. This field is best if it is combined with another field of study, as librarians with subject matter expertise in another field are especially valuable. The employment prospects in this field can be limited, since it involves work in libraries, which are often underfunded and under-staffed.

This video by a student in Korea is a good summary of the field of library science.

This article from the University of Tennessee is a good explanation of what a major in library science involves:

Understanding trends in media, computers/technology, Internet, and publishing is important to success in the profession. Virtually any undergraduate degree can offer good preparation for ALA accredited graduate programs.