ChemGlobe: Lead: Electronic, thermal, and steric data along with an isotope table.
ChemicalElements.com: Lead: Basic information, atomic structure, and isotopes table.
EnvironmentalChemistry.com: Lead: Atomic structure, chemical and physical properties, and table of nuclides.
Facts About Lead: Focuses mainly on the element's uses.
It's Elemental: Lead: Basic physical and historical information.
LANL: Lead: Properties, forms, uses, and handling.
Lead: Data tables and historic information.
Lenntech: Lead: Physical data, chemical properties, health and environmental effects.
USGS Minerals Information: Lead: Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).
Visual Elements: Lead: Image, uses, physical information, and key isotopes.
WebElements: Lead: Extensive information on history, uses, occurrence, compounds, and properties.
Wikipedia: Lead: Properties of the element, including its history, applications, and characteristics.