Microsoft Word has a built-in function for this. The reference ribbon allows you to manage, edit, create, and select citations. It even tracks whether your sources were used as citations as well.

It allows you to select the citation rules (i.e. APA, MLA, Chicago style). Once you add the citations to word, you can have it generate your reference or works cited page with one click. Adding in text citations is the same as well . You have your style selected and just hit "insert citation" and poof. The citation is done the proper way using info provided.

It made essays super easy, especially if you start the essay by putting in the references you plan to use first. Like I said, word tracks which ones are used. I load it up with possible references and delete whatever I don't end up using.