It's hard enough to keep track of all the information you gather when you do your own research. Once you add others to the mix of searching, finding, and gathering resources for research, it is vital to both keep track of your own contribution and to decide as a group on a method for collecting books, articles, web resources and the like. This page lists some tools especially good for harvesting information with a group.
EverNote is great for harvesting information -- especially images -- from the web. The main drawback is full sharing with a group. Only "Premium" members can have full group editing, though free members can share "view-only" access with group members to individual notes or whole notebooks.
Not a great collaborative tool, but a fantastic way to quickly save things you want to read later. Perhaps a good back-up tool to have on hand, or to use if you find yourself reading frequently from a mobile device.
Zotero is great for capturing web content and biblographic information about published documents, but it is not as robust as EndNote or Mendeley in features you'll want to use when culling and organizing what you've collected. Luckily, Zotero is good at exporting in formats that can be imported into EndNote and Mendeley.
Mendeley's strengths in importing lie in published documents. Straight web content is not easy to get into Mendely. Dragging and dropping PDFs into Mendeley desktop is pure magic.
MAJOR LIMITATION: free Mendeley only allows 3 members in a private group. You have to subscribe to use Mendeley private groups for four people. Or you can use a public, invite-only group, but that isn't ideal.
Drag and Drop PDFs into Desktop
Mendeley will harvest the bibliographic information from the PDF. You can also set up watched folders from which Mendeley will automatically import any PDFs you save there.
EndNote's strengths are in ingesting citations and documents from journal and book databases and catalogs. There are options for collecting web content, but they're not as smooth as tools created for that purpose. You can use EndNote to search databases directly, too.
You can share your citations with group members, but not the documents.
Check out these annotated lists of more...