Oxford English Dictionary, 2nd edition, ed. by J.A. Simpson and E.S.C.Weiner (New York: Oxford University Press, 1989).
Call number: PE1625.087 1989.
Size: Twenty volumes (9 x 12 inches), weighing a total of 138 lbs.; 21,728 pages;
291,600 main entries, 616,500 etymologies; 2.5 million quotations. Five
times as large as any other English dictionary.
History: Project initiated by the Philological Society in 1857. First published in 125 installments (1884‑1928) under the title New English Dictionary on Historical Principles. Published in 1933 in twelve bound volumes (including a supplement) under the title Oxford English Dictionary. Four supplementary volumes published, 1972‑1986. The second edition (1989) incorporates the supplementary material, and makes small number of additions and corrections. It is now published in both print and electronic formats. A third edition is in progress; two small volumes of new material have already been published.
Emphasis: Etymology and history of English words. Use the OED when you want extensive information about the origin of a word and hoe it evolved, along with examples of how past authors used it. It is a research tool. Don't use the OED merely to look up an unfamiliar word that you encounter; it is too cumbersome for that. Be especially careful about using it for science and technology (except for the history of their terminology), because much of the material is badly out of date.
National orientation: Chiefly British, especially in the first edition. A great many words and usages from the USA and other English‑speaking countries are now included, but they are not always treated quite as exhaustively as their British counterparts. Pronunciations still assume that the speaker has an upper‑class British accent.
Help for the user: If you are puzzled by the OED's abbreviations, pronunciations, typographical conventions, etc., consult the prefatory matter at the beginning of Volume 1.
Some other dictionaries: Webster's Third New International Dictionary (PE1645,W36; probably the most comprehensive one‑volume English dictionary); American Heritage Dictionary of the English Language (PE1625.A54; includes usage notes by a panel of famous people). Subject dictionaries: find them by doing a subject search for: [Subject name]‑-Dictionaries. For example, if you want a dictionary of music, look under Music‑-Dictionaries. (Note that dictionaries of the English language all have similar call numbers and are shelved together, while subject dictionaries have a wide variety of call numbers.)