MLA? APA? Chicago? You're not sure? It doesn't matter at first, because they're all basically the same, no matter how different they seem. All citation formats include these elements of basic bibliographical description: AUTHOR, TITLE, DATE, PAGE NUMBERS, VOLUME/ISSUE, and SOURCE. Most also include electronic identification for items on databases or online (web links and digital object identifiers or DOIs.)
However, some academic disciplines use a particular format. Your instructor will probably tell you which format style to use. If not, see the boxes below.
AUTHOR name(s)
DATE (location varies, but it's always required)
TITLE (books, articles, and journals)
VOLUME and ISSUE (for articles)
PAGE NUMBERS
SOURCE (publisher, journal info, "container," producer, website info, DOI)
Immediately upon finding a possible source (article, book, webpage, or whatever), make a record of these bibliographical elements, which are common to all styles and formats. Take notes, get a screenshot, check the book out, email the record to yourself, copy and paste the site URL, and put it in a folder...if you can't describe the source, you cannot ethically or honestly use it. See this handout about plagiarism of words and ideas.) Later, when you have time, format the information according to a standard. If you get stuck, check with your professor, a librarian, or a tutor.
Purdue University's Online Writing lab has been a nationally recognized reference for conventions of formatting and citation, as well as many other issues in writing.
Many databases also include a basic citation generator. Check the results, though; occasionally an error appears.
These books are the standards for style, format, and citation in their disciplines. Ask for them at the reference desk. (Earlier editions may be found in the Stacks.)
ACS (chemistry): QD8.5 .A25 2006 REF.
APA (social sciences): BF76.7 .P83 2020 REF.
Bluebook (law): KF245 .U55 2010 REF.
Chicago (humanities, history): Z253 .U69 2017 REF.
CSE (sciences): T11 .S386 2006 REF.
IEEE (engineering, computers, and IT). Ask at the reference desk.
MLA (humanities): LB2369 .M52 2021 REF.
Turabian (Chicago for students): LB2369 .T8 2018 REF.