ChemGlobe: Gold
   Electronic, thermal, and steric data along with an isotope table.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/79.html

ChemicalElements.com: Gold
   Basic information, atomic structure, and table of isotopes.
   http://www.chemicalelements.com/elements/au.html

EnvironmentalChemistry.com: Gold
   Atomic structure, chemical and physical properties, and table of nuclides.
   http://environmentalchemistry.com/yogi/periodic/Au.html

Gold Bulletin
   The peer reviewed journal on the latest science, technology and applications of gold. It includes papers on the latest research advances, reviews, conference reports, and highlights of patents and scientific literature.
   http://www.goldbulletin.org

It's Elemental: Gold
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele079.html

LANL: Gold
   Sources, properties, uses, cost, and isotopes.
   http://periodic.lanl.gov/elements/79.html

Lenntech: Gold
   Physical data, chemical properties, health and environmental effects.
   http://www.lenntech.com/Periodic-chart-elements/Au-en.htm

Radiochemistry of Gold
   Full text of the monograph by J. F. Emery (Oak Ridge National Laboratory, Oak Ridge, Tennessee). [PDF]
   http://lib-www.lanl.gov/cgi-bin/getfile?rc000062.pdf

USGS Minerals Information: Gold
   Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).
   http://minerals.usgs.gov/minerals/pubs/commodity/gold/

Visual Elements: Gold
   Image, general and physical information, source, uses, key isotopes, and ionisation energies.
   http://www.chemsoc.org/viselements/pages/gold.html

Wikipedia: Gold
   Properties of the element, including its history, applications, and characteristics.
   http://en.wikipedia.org/wiki/Gold

World Gold Council: Science and Industry
   Information about various different topics regarding gold.
   http://www.gold.org/discover/sci_indu/