I'd like to nominate yet a non-fiction book.
Aspects of the Novel by E. M. Forster
A delightful, witty, easily accessible set of talks on the topic of the novel. Relatively short, too
From
Amazon.com:
There are all kinds of books out there purporting to explain that odd phenomenon the novel. Sometimes it's hard to know whom they're are for, exactly. Enthusiastic readers? Fellow academics? Would-be writers? Aspects of the Novel, E.M. Forster's 1927 treatise on the "fictitious prose work over 50,000 words" is, it turns out, for anyone with the faintest interest in how fiction is made. Open at random, and find your attention utterly sandbagged.
Forster's book is not really a book at all; rather, it's a collection of lectures delivered at Cambridge University on subjects as parboiled as "People," "The Plot," and "The Story." It has an unpretentious verbal immediacy thanks to its spoken origin and is written in the key of Aplogetic Mumble: "Those who dislike Dickens have an excellent case. He ought to be bad." Such gentle provocations litter these pages. How can you not read on? Forster's critical writing is so ridiculously plainspoken, so happily commonsensical, that we often forget to be intimidated by the rhetorical landscapes he so ably leads us through. As he himself points out in the introductory note, "Since the novel is itself often colloquial it may possibly withhold some of its secrets from the graver and grander streams of criticism, and may reveal them to backwaters and shallows."