The Craft of Research by 
Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research. It helps you track all your sources build bibliographies in minutes! It's also collaborative, so if you're working on a project with multiple people you can all save your sources in one place!
Zotero Tutorials
This LibGuide from Ohio University has great video tutorials on using Zotero.