Different disciplines use different citation styles for various reasons. Be sure to consult with your professor before you choose a specific style to work with.
The Chicago Manual of Style contains guidelines for two types of citations. These are Notes and Bibliography style and Author-Date style. If you don't know which type of citation to use, consult your instructor. It is important, however, that you only use one style in any given paper, so pick a style and stick with it.
How do I create citations in Notes and Bibliography Style?
How do I create citations in Author-Date Style?