To dream that you are in a library, denotes that you will grow discontented with your environments and associations and seek companionship in study and the exploration of ancient customs.
To find yourself in a library for other purpose than study, foretells that your conduct will deceive your friends, and where you would have them believe that you had literary aspirations, you will find illicit assignations.
Dreams of libraries are strong suggestions from the unconscious mind that the dreamer needs to find meaning in his/her life. Also see Book.
You may be trying to assimilate some new information or idea.
A library is a place of learning and is generally a good dream image. It suggests that you may be close to solving a problem or discovering something new and exciting.
A library is a repository of knowledge and assessable information, and a dream featuring a library may be showing you that you need to learn all you can about a certain thing or situation before becoming involved, and if you are checking out a book you will need to ‘check out your information’.
If you are returning books, then this is a wish you have for teaching another.