ChemGlobe: Aluminium - Electronic, thermal, and steric data along with basic information. - http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/13.html
LANL: Aluminum - History, sources, uses, and compounds. - http://periodic.lanl.gov/elements/13.html
Wikipedia: Aluminum - Details the properties of the element, including its history, applications, and characteristics. - http://en.wikipedia.org/wiki/Aluminum
Lenntech: Aluminum - Physical data, chemical properties, health and environmental effects. - http://www.lenntech.com/Periodic-chart-elements/Al-en.htm
Aluminium versus Aluminum - The different American spelling of what British English spells 'aluminium' sometimes cause puzzlement as to how it could have come about. This article tells that story. - http://www.quinion.com/words/articles/aluminium.htm
USGS Minerals Information: Aluminum - Overview and a number of publications in PDF format. - http://minerals.usgs.gov/minerals/pubs/commodity/aluminum/
ChemicalElements.com: Aluminum - Basic information, atomic structure, and table of isotopes. - http://www.chemicalelements.com/elements/al.html