FSX Add-ons and useful online flight sites

FSX, FS2004 Aircraft, Textures, Scenery Add-ons

fsdownload (freeware)

http://www.fsdownload.com/

Project Open Sky or POSKY (freeware - highly recommended)

http://www.projectopensky.com/

Simviation (free and payware)

http://simviation.com/menu.html

Wilco Publishing (payware aircraft)

http://www.wilcopub.com/index.cfm?fuseaction=home

PMDG (payware aircraft)

http://www.precisionmanuals.com/index_css.html

Online flight useful sites (reality flight)

VATSIM (Virtual Air Traffic Simulation Network)

http://www.vatsim.net/

Flight Aware (online flight tracking)

http://flightaware.com/

Aero Planner (flight planner, professional use - pay service)

http://www.aeroplanner.com/

I will update this list with more details