Many databases format citations you have found into one of the common styles.
Look for "Cite this" or "Cite" or a similar link.
Be sure and ask your instructor which of the style guides you should use.
You can also visit the
Purdue University Online Writing Lab (OWL),
which provides online, user-friendly, comprehensive guides for students with many examples of how to cite print and non-print sources in the most common writing styles, such as APA.