Zotero is a free, open-source citation tool that works with Chrome and Firefox. It allows you to collect metadata that can be inserted into Word as citations and bibliographies.
Strengths of Zotero
Getting Started with Zotero
To get the most out of Zotero, use the Zotero: Getting Started guide. It will walk you through installation and configuring the tool to work with Harvard Library resources.
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.