The original work, as far as I know, on this topic is great for nostalgia buffs wanting a return to the fifies: Robert A. Hall, Jr.’s Leave Your Language Alone. I read the later edition titled Linguistics and Your Language.
Jim Quinn’s American Tongue and Cheek is written by a journalist who simply used the OED to demolish the shibboleths of the “language mavens’.
Language mavens is Steven Pinker’s term for those Sunday supplement language critics who look down their noses at people who end a sentence with a preposition and, in John Simon’s famous words, “are too stupid to know the nominative case from the accusative”. Anyone you know?
You’ll find the chapter on the language mavens in Pinker’s famous The Language Instinct.
A couple of other books which take on the issue of what is correct are Ronald Wardaugh’s Proper English, Frank Palmer’s Grammar and Jean Aitchison’s Language Change: Progress or Decay and Teach Yourself Linguistics in the TY series.
For those who find linguists politically suspect as a bunch of Noam Chomsky-type lefties, one of the best of the up-and-coming young linguists is the prominent conservative spokeperson on racial matters, John McWhorter. He has written Word on the Street that even a staunch liberal like myself finds excellent.
McWhorter has also written a terrific popular book on linguistics (not an introduction but you might use it as one): The Powe of Babel. Fascinating. As a linguist, McWhorter’s take on things is, well, breath-taking; politically….. another story.
I have mentioned Aitchison’s book on linguistics; in addition to hers, there’s R.L. Trask’s Language: The Basic, an unusual and very effective introduction to the basic concepts of linguistics; a good book for those who think linguists are a bunch of lefties out to destroy Amerika by weakening our ability to communicate through squishy and wishy-washy grammar rules.
For an overview of English, you can dip into David Crystal’s Cambridge Encyclopedia of the English Language. There’s a lot on prescriptivism in there.
Finally, for fun, read David Wilton’s Word Myths. He demolishes many of the “accepted? folk etymologies (he ruined one of mine when he revealed that “in flike Flynn? is not about the Great Errol’s amorous pursuits).
Remember, we are all prescriptivists when we prescribe for students the forms used in SE or the FL we teach. But Prescriptivists with a capital P are a special group who, while maybe well-intentioned if a bit cantankerous, can do harm in the teaching of the standard.
There are other books on my shelf, but I haven’t read them yet. And there are many other books in the library. Mention any of them on my blog, with your own review.