"A very basic way of thinking about literary theory is that these ideas act as different lenses critics use to view and talk about art, literature, and even culture."
The Online Writing Lab (OWL) at Purdue University provides a brief overview of major schools of criticism.*
Reference books are good places to start your research when you know little about a topic, need an overview of a subject, or want a quick summary of basic ideas. They are also useful for discovering the names of important people and can familiarize you with the vocabulary of the field.
Etymology traces "the roots of our language and shows its many points of contact with the other cultures...Explanations about the development of particular words in a language are probably as ancient as language itself." (Preface, Barnhart Dictionary of Etymology)
The etymology of words are contained in dictionaries. Booth Library owns several excellent etymology dictionaries and can also recommend an open access option.
For a complete list of etymological resources, check the Library Catalog, below is a short list of available resources: