The Ethernet Standards:

The IEEE has a program that offers free online copies (PDF format) of IEEE standards, including the Ethernet 802.3 standard, at: http://standards.ieee.org/getieee802/. Once you have agreed to the IEEE's Terms and Conditions then select IEEE 802.3: CSMA/CD Access Method for access to an online copy of the latest version of the Ethernet standard.

The "Get IEEE 802" Web site describes the program that provides free online copies, and explains which versions of the standards are made available through the program:

"The Get IEEE 802® program makes IEEE 802® standards available at no charge in PDF format ... This program grants public access to view and download current individual IEEE Local and Metropolitan Area Network standards at no charge.

New IEEE 802® standards will be included in the program after they have been published in PDF for six months.
All documents available in the Get IEEE 802® program will remain in the program until they are replaced by a superseding document or they are withdrawn.
Drafts are not part of the program, but can be purchased individually from Shop IEEE.
New, Superseded, and Withdrawn standards can be purchased by visiting the Shop IEEE . or accessed by subscribing to IEEE LAN/MAN plus Drafts Standards Online Subscription."

IEEE Working Group:. The evolving Ethernet standards and a variety of study documents used in the development of the 802.3 technical standards may be found on the 802.3 Working Group section of the IEEE Standards Association Web site.

IEEE Organizationally Unique Identifier (OUI) page. This page describes what an OUI is and how to purchase an OUI assignment from the IEEE.

IEEE Type Field page. This page describes what a Type field is and how to request a Type field assignment for new protocols.