Zotero is a free, open-source citation tool that works with Chrome, Firefox, and Safari. It allows you to collect metadata that can be inserted into Word as citations and bibliographies.
Use the Zotero: Getting Started guide to find out more about installing and getting the most out of Zotero. To sign up for a Zotero class or to get help with using the tool, go to https://guides.library.harvard.edu/cite/
Do you just need to produce a quick bibliography? Try ZoteroBib to create a bibliography quickly in a variety of citation styles without creating an account or installing any software.