Zotero is a free, open-source research management program that lets you to save and organize your sources as you research. When it's time to write, you can then insert your sources directly into your paper as in-text citations, footnotes, and bibliographies (references) via a word processor plugin.
Benefits of Zotero:
- Web browser plugins make it easy to save item information from the web
- Good at capturing and downloading full-text PDFs from databases
- Built-in tool to extract source info from PDFs
- Supports virtually all citation styles
- Word processor plugins let you to "cite as you write"