Florida-Spectrum Environmental Services
Florida Spectrum: Chemical Fact Sheet: Rhodium
Nice thorough entry on rhodium from SpectrumLabs, its properties and uses.
Chemicool
Chemicool: Rh45 Rhodium
Set of tables from Chemicool summarizing many physical and chemical properties of rhodium.
Corrosion Source
Corrosion Source: Rhodium
Gives good basic information on rhodium, its history, sources, uses and properties.