Uniformly documenting your research is essential for reasons other than "My teacher told me to." It helps those who read your work to find the interesting things you cited and expand their knowledge, and it allows you to keep track of all of the sources you used. After all, you may want to consult them again down the road for a different assignment!
Remember, the style you have to use isn't just about citing sources. Your work should be formatted correctly, too. Style guides dictate whether you need a title page, footnotes, and what to call the page with all of your citations (Bibliography, Works Cited, etc.). Consult the style manuals and links on this page for help with both formatting and citing.
The Social Sciences usually use the APA (American Psychological Association) or Chicago Manual of Style for formatting and citations. Those in Political Science may also be asked to use APSA (American Political Science Association) formatting and citation styles. Copies of the most recent editions of most guides are kept at the reference desk on the first floor of the library.
Many databases will generate a citation for you in the style of your choosing. They're not always perfect, but they provide a helpful start. The image below is what this will look like in EBSCO databases, but in general, look on either the left or right sides of the article or detailed record to find this feature.