I hardly ever read books by people who are primarily known for something other than writing them, and this is a good example of why not.
The blurb makes this book sound fascinating, at least, if you have any interest in the Supreme Court. "With unparalleled insight and her unique perspective as a history-making figure, Justice O'Connor takes us on a personal exploration.... We get a rare glimpse into the Supreme Court's inner workings: how cases are chosen for hearing; the personal relationships that exist among the Justices; and the customs and traditions, both public and private, that bind one generation of jurists to the next...." Unfortunately, that's just the publishers' wishful thinking; barely a word of what I just quoted is true. Well, except for the public traditions: the book spends a good 11 pages on oath-taking. But "candid" it is decidedly not.
Essentially, Out of Order is a brief (165 pages of text, followed by the Declaration of Independence, Constitution and references) and basic introduction to the U.S. Supreme Court. Its chapters covers topics such as famous clashes between the Court and the presidents; the various buildings in which the Court has been housed; the early tradition of circuit-riding; and biographical sketches of a few famous justices.
Justice O'Connor handily avoids the opportunity to include personal insights, stories or opinions. For instance, the chapter on judicial appointments simply lists presidents, their appointees, and what the people in question are best-known for, without a hint of an opinion on the appointment process or discussion of the author's own confirmation hearings. And rather than providing insight into how the Court chooses which cases to hear, O'Connor simply quotes the relevant Supreme Court Rule. The deepest this book gets into the inner workings of the Court is the description of the Justices' lunches: everyone sits in the chair occupied by their predecessor, and talk about work is not allowed. What they actually do discuss, or how justices with strongly opposed views relate to each other personally, the book doesn't say. But even the lunchtime "insight" is rare; 99% of this book could as easily have been written by someone with no personal knowledge of the Court.
In fairness, I came to this book knowing a lot about the topic already, and while it's clearly mismarketed, it may not be a bad choice for high school civics classes, or for those who just want to gain some basic knowledge about American public institutions. I certainly learned some new trivia, and some of the anecdotes are enjoyable and piqued my interest in lesser-known historical figures: particularly Justice Field (the story of his judging in the Wild West begins with his pointing a gun at a juror, and gets crazier from there) and Belva Lockwood (who successfully lobbied to have women admitted to practice before the Court.... in 1879).
But even for those with little prior knowledge of the Court, this book would have benefited from either more personal insight, or a greater depth to its treatment of history; as it is, the book focuses on basic information and trivia, provides little explanation or analysis, and fails to elaborate on potentially fascinating stories. While a quick read, it consists mostly of the sort of information available on Wikipedia, and for that reason, sadly, I can't recommend it.