Societies
American Association of Variable Star Observers http://www.aavso.org/
American Meteor Society http://www.amsmeteors.org/
Association of Lunar and Planetary Observers http://alpo-astronomy.org/
Astronomical League https://www.astroleague.org/
Astronomical Society of the Pacific https://www.astrosociety.org/
International Dark-Sky Association http://www.darksky.org/
International Association of Double Star Observers http://www.iadso.org/
International Meteor Organization http://www.imo.net/
International Occultation Timing Association http://occultations.org/
The Planetary Society http://planetary.org/