Two books on writing: Francine Prose’s Reading Like a Writer: A Guide for People Who Love Books and for Those Who Want to Write Them and Stephen King’s On Writing: A Memoir of the Craft. Read Prose for practical advice (her main argument is that the writer should be concerned with writing good language, beginning with a good sentence, and ignore trends and fashion) and sheer enjoyment of good writing (with many examples). Read King for inspiration (the book is partially a memoir of his career, partially an exhortation to just write, with fairly simple advice, most notably "Second draft = First draft – 10%".)

Actually, both are good for inspiration, countering the dread of entering an airport bookstore and realising you have read it all….