The below video from the North Carolina State University Libraries explains the basics of citation: what it is and why we do it.
The following handouts and online tutorials address how to integrate sources into your writing & how to avoid plagiarism:
Purdue University's OWL (Online Writing Lab) provides an extremely detailed online guide to formatting and citation according to the MLA Handbook (8th. ed.).
Check the RWC workshop schedule for in-person workshops on citation and documentation.
You can consult a copy of the MLA Handbook (8th ed., 2016) at Cooperman Library. There is 1 copy on Reserve (it may be checked out from the Circulation/Reserves Desk for 2 hours at a time, for use in the library only), and there are 2 copies available for short-term use at the Welcome Desk (just inside the entrance on the 3rd floor).