You can keep track of citations and PDFs using citation management software. Zotero is a free open-source reference data manager.
For information on using Zotero, check out our guide. If you want to jump in and get started, use these links:
The online and desktop versions sync together, allowing you to access your files from any internet-connected computer.
The library gives presentations on using Zotero; if a group of students is interested in setting up a session outside of class time, let me know!