This is not every good Singularity site. This is just the short list of sites you need to visit or you won't have a clue.
Verner Vinge's Singularity speech
Eliezer Yudkowsky's "Staring into the Singularity"
Ray Kurzweil's "Law of Accelerating Returns"
Marshall Brain's article "Robotic-Nation"
K. Eric Drexler on nanotechnology.
Ralph Merkle on nanotechnology.
The Foresight Institute's preview page of Nanomedicine by Robert A. Freitas Jr.
Cryonics, if you can't wait for the Singularity.
The Human Genome Project goes on.
World Transhumanist Association
Center for Responsible Nanotechnology
Singularity discussion site by John Robb.
The Google web Directory on the Singularity.
Paths to the Singularity. By Daniel G. Clemmensen
The official Delphi Forum SingularityActionGroup. owned by one of our own Directors, Sharon Brown.
The official Wiki SingularityActionGroup Wiki. maintained by our CEO, Deepak Goel.
Yahoo group: Singularity
Mind-Brain.com Singularity discussion forum
Shock Level 4: SL4 hosted by Eliezer Yudkowsky research fellow SIAI, and all around Singularity expert.
World Transhumanist Association
Singularity Action Group website frames version.