What is metadata and what are some of it's functions?

Metadata is data about data. It is the description and context of data. Metadata helps organize, find and understand resources. Metadata could include information such as title, creator, date created, location created, description, subject, etc. Metadata is important because it assists in the discoverability of information.

What are the origins of early public libraries?

As antiquity ended religious institutions began to take over the functions of ancient government and private libraries. In Western Europe, Catholic monks collected and created written texts. In Muslim countries, Imams and other scholars used printing techniques developed by the Chinese to create collections of written texts. Early libraries were created to house Qur’anic texts but also included early developments in astronomy and mathematics by Arabic scholars. As the Renaissance and later the Enlightenment movements spread throughout Europe secular libraries began to develop. Bartolomeo Platina’s library and the Austrian National Library are two examples. Scholars collected and produced written texts on philosophy, mathematics, religion, and science. After the creation of the Gutenberg Printing Press libraries began to store not only ancient texts but modern books as well. These libraries were usually only open to scholars or the aristocracy. Public libraries that allowed access to anyone wouldn't be constructed until after the founding of the United States.

I'm study the reconstruction era in the American South and I'm looking for more information on the U.S. Supreme Court cases Plessy vs. Ferguson. Is there anywhere where online where I can find a transcript of the entire case that I would be able to reference in a paper?

I would suggest trying the website www.oyez.com. The website is free law project from Cornell’s Legal Information Institute, Justia and Chicago-Kent College of Law devoted to making the Supreme Court of the United States accessible to everyone. Users are able to search cases by name or court term. Each case includes a summery and annotations plus a transcript of the case. It is an outstanding resource. Also check your local public library for free legal resources.