ChemGlobe: Iodine
   Electronic, thermal, and steric data along with an isotope table.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/53.html

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

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

It's Elemental: Iodine
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele053.html

LANL: Iodine
   History, sources, uses, properties, and isotopes.
   http://periodic.lanl.gov/elements/53.html

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

Radiochemistry of Iodine
   Full text of the monograph by Jacob Kleinberg (University of California, Los Alamos Scientific Laboratory, Los Alamos, New Mexico and University of Kansas, Lawrence, Kansas). [PDF]
   http://lib-www.lanl.gov/cgi-bin/getfile?rc000043.pdf

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

Visual Elements: Iodine
   General and physical information, source, uses, biological role, key isotopes, and ionisation energies.
   http://www.chemsoc.org/viselements/pages/iodine.html

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