See also Mendeley's Guide to Organizing Your Mendeley Library
You can use Collections in Mendeley Reference Manager to organize your documents in whatever collections make sense to you. Documents can be in more than one collection. Look for the New Collection link in the left pane in Mendeley Reference Manager.
You can assign tags to each document in your Library and use these tags to help to locate and organize documents.
You can also use the star icon to add documents to your Favorites list, and mark documents as read or unread using the green dots.
