Overview of Ethernet by Cisco - Ethernet history, topologies and physical layers. - http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ethernet.htm
ISO/IEC 8802-3:1996 - One of standards broadly associated with "Ethernet", ISO/IEC 8802-3. - http://www.iso.org/iso/en/CatalogueListPage.CatalogueList?ICS1=35&ICS2=110
What Is...Ethernet - Definition from Whatis.com. The most commonly installed carrier protocol technology for local area networks. - http://whatis.techtarget.com/definition/0,289893,sid9_gci212080,00.html
TechFest Ethernet Technical Summary - A largely complete overview of all Ethernet standards including Frame Structure, MAC, Physcial Layer, and cabling. - http://www.techfest.com/networking/lan/ethernet.htm
How Stuff Works: Ethernet - Eleven-segment illustrated tutorial about Ethernet networks, with related net links. - http://www.howstuffworks.com/ethernet.htm