ChemGlobe: Uranium: Electronic, thermal, and steric data along with an isotope table.
ChemicalElements.com: Uranium: Basic information, atomic structure, and isotopes.
Depleted Uranium: Information about depleted uranium in question and answer form.
EnvironmentalChemistry.com: Uranium: Atomic structure, chemical and physical properties, and table of nuclides.
It's Elemental - Isotopes of the Element Uranium: Has an extensive list about the isotopes of uranium. Gives mass number, half life, branching percentage, and decay mode of the isotopes.
It's Elemental: Uranium: Basic physical and historical information.
LANL: Uranium: Sources, properties, isotopes, and uses.
Lenntech: Uranium: Physical data, chemical properties, health and environmental effects.
Radioactive Byproducts of Depleted Uranium (Uranium-238): Shows the byproducs of depleted uranium and shows their half-lives.
The Element Uranium: Basic and advanced technical details and history concerning uranium.
UIC - Uranium & Nuclear Power Information Centre: The UIC web site is to assist public understanding of uranium mining and nuclear electricity generation.
Uranium: Several data tables with information about the properties of uranium, as well as an extensive history about it.
Uranium (Element): Some quick facts about uranium, including all the basic info.
Uranium and Its Compounds: Facts about uranium and its compounds, including physical and chemical properties, uses, and possible health effects.
Uranium-235 Chain Reaction: Shows examples uranium reactions in fission, as well as data about those reactions.
Uranium: Properties: Element: Very extensive information about the chemical/physical properties of uranium. Information includes the occurrence of uranium, isotopes, and spectrum.
Visual Elements: Uranium: Image, animation, source, use, and key isotopes.
WebElements: Uranium: Extensive information on history, uses, occurrence, compounds, and properties.
WebElements: Uranium: Has extensive information about the properties of uranium.
WHO: Depleted Uranium: Information about depleted uranium and its potential health effects.
Wikipedia: Uranium: Properties of the element, including its history, applications, and characteristics.