Lead

ChemGlobe: Lead - Electronic, thermal, and steric data along with an isotope table.
http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/82.html

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

It's Elemental: Lead - Basic physical and historical information.
http://education.jlab.org/itselemental/ele082.html

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

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

WebElements: Lead - Extensive information on history, uses, occurrence, compounds, and properties.
http://www.webelements.com/lead/

Visual Elements: Lead - Image, uses, physical information, and key isotopes.
http://www.chemsoc.org/viselements/pages/lead.html

LANL: Lead - Properties, forms, uses, and handling.
http://periodic.lanl.gov/elements/82.html

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

ChemicalElements.com: Lead - Basic information, atomic structure, and isotopes table.
http://www.chemicalelements.com/elements/pb.html