Dance organizations

http://www.usadance.org - Official USA Dance website
http://www.nyusadance.org - USA Dance New York Chapter
http://www.idsf.net - The International DanceSport Federation
http://www.ndca.org - The National Dance Council of America
http://www.istd.org - The Imperial Society of Teachers of Dancing

Dance studios in Manhattan

http://www.dancechelsea.com
http://www.manhattanballroomdance.com
http://www.ballroomoff5th.com
http://www.dancesport.com
http://www.steppingoutstudios.com
http://www.dancestudio101.com

College team websites

http://webscript.princeton.edu/~pbdc/ - Princeton Ballroom
http://www.ballroomatmaryland.com/ - Ballroom at Maryland
http://www.yale.edu/ballroom/ - Yale Ballroom
http://www.dolphin.upenn.edu/ballroom/ - UPenn Ballroom
http://www.nyuballroom.com/ - NYU Ballroom
http://www.harvardballroom.org/ - Harvard Ballroom
http://ballroom.rutgers.edu/ - Rutgers Ballroom
http://ballroom.mit.edu/ - MIT Ballroom

Other dance resources

http://www.dancepartner.com - Partner search
http://www.ballroomdancers.com - Ballroom resources
http://www.danceshopper.com - Dance supplies
http://www.championshipdancecamps.com - Dance camps
http://www.dance-forums.com - Dance discussions