Zotero is an easy to use citation manager. It can help you collect, save, and organize a variety of resources. The web version is connected to your browser. It is designed to do research in the digital world, and can accurately sense the type of material being viewed. Since it is open source there are a number of 3rd party tools associated with the application.
To get started:
CLICK HERE for Zotero's Quick Start Guide.
Georgia State University's Zotero Guide created by Librarian Jason Puckett
While this video is from another course what is being covered applies perfectly to any user of Zotero wanting to share references.