Market Resources:

The Market List
http://www.marketlist.com

Mary Soon Lee's Market List
http://www.cs.cmu.edu/~mslee/mag.html

Paula Fleming's Market List
http://home.att.net/~p.fleming/Sfmarket.html

Ralan's Webstravaganza
http://www.ralan.com

Spicy Green Iguana
http://www.spicygreeniguana.com

Submitting to the Black Hole
http://critters.critique.org/blackholes/

Writers Resources:

Speculations
http://www.speculations.com

Science Fiction Writers of America
http://www.sfwa.org

Holly Black's Writing Resources
http://www.blackholly.com/writingresources.htm

On-line Crit Groups:

Critters
http://www.critters.org

Imaginaries
http://www.imaginaries.org

Professional Workshops:

Clarion
http://www.msu.edu/~clarion/

Clarion West
http://www.sff.net/clarionwest/index.htp

Odyssey
http://www.sff.net/odyssey/

Viable Paradise
http://www.sff.net/paradise/