Read quickly. You’re not being paid enough to spend quality time with this book, and besides, you can usually tell within the first five pages whether the author has written the book you want to read, or something that merits only scorn. You can try opening it at random and reading ten different pages to get a flavor of it. Or make like Marshall McLuhan and read — or rather skim — just the odd-numbered pages.
If it’s a novel, you’re not supposed to give away the ending in any case. Reading all the way to the end is for suckers and college interns eager to suck up to the editor. The important thing is to demonstrate critical acumen in the review, which is best done by adopting a tone of lofty condescension, unless the author is a friend or someone who might conceivably be asked to review your own next book, in which case you are better off to hail the work as groundbreaking while at the same time naming other writers in the same genre to which is bears a close resemblance. These writers can be selected more or less random — the more off-the-wall the comparisons, the more you’ll come across as eclectic and perceptive (not to mention well-read).
Important note: don’t be too hasty in emailing this off to your editor. Fact-check to make sure you have the basic details right, such as the main character’s name and situation. If you screw that up, you risk blowing your cover and looking like a total dumb-ass.
Poetry is a trickier case, but one rarely encountered by the professional reviewer, since so few major publications want to risk driving away readers with reviews whose sole value is to garner a little extra high-brow credibility for the publication. If you are called upon to review a book of poetry, the safest approach again is to open the book in a number of places at random. Select four or five reasonably interesting quotes, decide what they likely mean in the context of the book as suggested by the blurbs and publisher’s description, then decide whether or not this is the sort of poetry you like and respond appropriately, either with fulsome praise or scathing condemnation. Since the American poetry scene is riven by factionalism, such extremes of rhetoric are the norm.
Poetry review editors also sometimes ask for three or four books to be included in the same review. On the surface, this might seem to make your job even harder, but not really. Now you only need to find one or two exemplary quotes per book, and their greater variety will push you to greater heights of creativity in your connective prose. If you’re really feeling puckish, and if the publication isn’t one that specializes in poetry, deduce a trend. Whatever you do, don’t engage with the subject matter of the poems, unless to belittle the poet (Sharon Olds’ obsession with sex, Mary Oliver’s rhapsodies about nature). You’re better than that. Remember, poetry is all about language, in the same way that painting is all about paint. Leave the achingly sincere analyses to the Christian Science Monitor and small-time bloggers.