Zotero is a free, "powerful, easy-to-use research tool that helps you gather, organize, and analyze sources and then share the results of your research." Zotero works within your browser and is excellent for extensive projects or managing multiple research topics.
Zotero Reference Manager from Ithaca College Library
EndNote Web is another free online tool. Very helpful documentation is available. Can include attached documents. Can export to other citation managers. Can export directly from VSC Online Catalog to EndNoteWeb. Can export directly from EBSCO databases, for others: generate an .ris file.
Publication Manual of the American Psychological Association by PowerNotes is a Chrome extension that allows you to collect quotes from online resources, annotate them, organize an outline, and generate the outline as the skeleton of your paper.