Zotero

• Helps researchers to collect, organize, verify & fix citations; and to add citations into Word
   
• Is open source software with 300 MB of storage for free
   
• Works with Windows, Mac, and Linux systems

Although Zotero automates many processes for you, the output isn't always 100% correct. You will need to be familiar enough with your style so that you can verify and fix the formatting in Zotero before you use the citations in your document.

• How to verify formatting
• How to fix formatting 

When on networked computer, you can add and edit items in your online zotero.org library, but you cannot use it to cite in Word.