A wealth of papers on social networks, online community, social capital on the Internet, and more. Some brand-new, some older. Most are available in PDF.

Capitalizing on the Internet: Network Capital, Participatory Capital, and Sense of Community
Computer Networks as Social Networks
Does the Internet Increase, Decrease or Supplement Social Capital?
The Internet in Everyday Life
The Persistence and Transformation of Community: From Neighbourhood Groups to Social Networks
Studying Online Social Networks

Barry Wellman's Publications