This important gathering of previously uncollected and unpublished material enlarges the assessment of O’Hara as a craftsman and a conscious literary artist.     O’Hara’s preoccupation with the craft of writing is superbly revealed in the series of lectures he gave on the Amer­ican novel at Rider College in Trenton, N.J. These hitherto unpublished lec­tures contain major critical statements about the techniques of fiction writing. O’Hara had intended to publish these lectures because of their importance, but he never did. Today they are of particular value in illuminating the thought of this eminent author because O’Hara developed them in close refer­ence to his own work and because they were written in 1959 and 1961 when he was at the peak of his writing career.   The 38 other pieces include the never-published foreword O’Hara wrote for The Selected Stories of John O’Hara. There are also three pieces on F. Scott Fitzgerald which reveal much about Fitzgerald and his writings. Other re­views and interviews show the high re­gard O’Hara had for his fellow writers—Faulkner, Hemingway, and Thorn­ton Wilder.   Like all good writing about writing, the material stimulates the reader to read or reread Appointment in Samarra, Rage to Live, Ten North Frederick, From the Terrace, Butterfield 8, and the col­lected short stories of this superb story­teller.