Inklings, a biweekly newsletter for writers on the net
http://www.inkspot.com/inklings/

Maryland Romance Writers
http://www.geocities.com/Paris/Parc/1468/

Novelists, Inc.
http://www.ninc.com

One Woman's Writing Retreat
http://www.prairieden.com/

Online Journalist
http://www.online-journalist.com

Purdue University On-line Writing Lab
http://owl.english.purdue.edu/

Writer's Guild of America
http://www.wga.org

Writer's Resource Center
http://www.azstarnet.com/~poewar/writer/writer.html