When I’m reading articles online, what is the best way of logging citations?

Columbia University Libraries supports three citation management software products:

EndNoteRef
Works
Zotero
All three products enable you to retrieve and save references from bibliographic databases so that you may later use that information in formatting in-text citations, footnotes, endnotes, and bibliographies. To download one of these programs, go to Options for Citation Management on the Columbia University Libraries site.