Plagiarism is described in the W&L 2018-19 Catalog, and cited by the Student Executive Committee, as "the use of another's words, figures, or ideas without proper ackowledgement." The resources listed here should be considered reliable sources of advice about what constitutes plagiarism and how to avoid it.
Unfortunately, there is no universally agreed-upon "style" for documenting the use of sources in research -- no single method for formatting footnotes, bibliographies, endnotes, in-text citations, etc. Instead, there are more than a dozen, most of which are specialized for use in one or more subject areas.
The W&L University Library maintain a collection of resources on these styles:
Please note that most of these resources are online, but some of the most important volumes still are available only in printed form.
A journal article's literature review discusses the existing research on aspects of the topic. Here is an example of a scholarly journal article which opens with a literature review, although it is not clearly labeled: Damaging and Daunting
And here is an example of an entire article devoted to a literature review: Enduring Themes and Silences in Media Portrayals of Violence Against Women