Zotero

Instructions on how to download, install, and use Zotero, a free open source citation management program.

Zotero Sync

Zotero's sync feature is an excellent way to create a backup for your research. It also enables you to work on your research at multiple computers. Zotero can store a copy of your library on the Zotero.org server and check it for updates whenever you open your library on a different computer. All your computers must be running the same version of Zotero.

First, set up a (free, of course) Zotero.org user account.

Zotero User Registration

Then:

Open Zotero Settings to get to Sync (Select Edit > Settings > Sync).
Enter your Zotero user name and password.
Check the "sync automatically" and "Sync full-text content" boxes.
Check both boxes under File Syncing and choose Zotero storage for My Library. This will sync your PDF attachments as well as citations (more info).
Click the two circular arrows (depending on your version) at the top right corner of the Zotero library.
Zotero will upload your library to the server.

Zotero Syncing
While Zotero stores all data locally on your computer by default, Zotero's sync functionality allows you to access your Zotero library on any computer with internet access. Zotero syncing has two parts: data syncing and file syncing.

Repeat this configuration on each of your computers. Any updates you make on one of your computers will be reflected on the others. This process even works to synchronize your library among Windows, Mac, and Linux computers.