I tend to address more of my blog posts to my fellow writers than to any one else, and I'm frequently scolding them for bad writing or bad behavior. Today I'm going to look in the other direction.
Except when we're writing just for ourselves, we writers depend on you, our readers, to make our stories come alive in your minds and your imaginations. It's our job to provide you with the tools -- the words -- to do that, and then it's your job to tell other readers whether we succeeded or failed.
No, it's not your job to tell us we didn't do it. We had our chances to get critiques before we published. We had the responsibility make sure the research was right, the words were right, the spelling was checked, the plot was seamless, the characters fully fleshed. Regardless how you acquired the book -- free, purchased, ARC, contest give-away, borrowed from a friend or the library, even illegally downloaded -- you invested your time in reading it. You have a right to your opinion because you made that investment.
Did you quit after the first page because the writing was so poor? You have a right to say so. You have a right to write a review that's longer than the portion of the book you read.
Were you so enchanted by the story that you never noticed how often the Regency heroine referred to the mysterious lights "left on" in the tower window? You have a right to say so.
You're allowed to say you didn't like the cover, that you're tired of characters named after objects like Link and Star and Storm and Blade. You're allowed to be snotty and snarky and mean. By the same token, you can gush and give it five stars (or whatever the highest ranking is) just because it's set in Paris and there's a dog in it somewhere.
Readers and reviewers can write revenge reviews. Is it kinda juvenile and silly to do so? Yeah, I suppose so. But we writers need to understand and accept that readers have all kinds of reasons for reading (or not reading) a book, for liking (or not liking) a book, and for liking (or not liking) an author. When we put our books out there and ourselves with it, we are inviting you to read them and we should not think that we have any control whatsoever over the reasons that motivate a person to pick up a book and read it. That includes anger or resentment or jealousy or spite.
Do you owe us anything? Nope. Nothing.
You don't owe us a review or a rating at all. You don't owe us a critique. You don't owe us a reading of the whole book. You don't owe us perfect grammar or spelling. First of all, you don't owe us anything because any review that you write isn't for us anyway. Reviews are for other readers. And it's okay to tell other readers that you couldn't get past page one. There are some really crappy books out there, and you shouldn't be surprised if you encounter a few. It's okay to tell other readers the author can't write her way out of a wet paper bag. Your job as a reviewer is not to be kind to the writer who threw that garbage; it's to let other readers know you think it's garbage. Reviews are for other readers. It's okay to correct each and every grammar error. It's okay to fill your online review with pictures and GIFs and videos and music and whatever else you want.
You didn't hang over our shoulders and tell us how to write our books. And we damn sure shouldn't be hanging over your shoulders telling you how to read them or how to review them.
Dear readers and reviewers, please don't ever be intimidated, harassed, or threatened by an author (or her friends, fans, or sockpuppets) who tries to tell you what's wrong with your review. Tell 'em to sod off. And if they won't, then tell 'em I told you to tell 'em there's no such thing as a stupid question, and there's no such thing as a wrong review. There is no "right" way to review and there is no "wrong" way to review. There is only your way.
Not liking a book, for whatever reason, does not make you a bully. Telling the author not to quit his or her day job does not make you a bully. Pointing out errors of fact does not make you a meanie or a troll. Reviewing a book you couldn't get past page 3 does not make you a criminal. You don't have to provide constructive criticism, and you don't have to be gentle with the tender sensibilities of the writer. If she didn't think she could take criticism, she shouldn't have published the thing.
You, the reader/reviewer, do not have to have perfect grammar and spelling. (Although if you correct someone else's and you're wrong, well, be prepared to have that pointed out!)
You don't even have to review. Did the author give you a free copy in exchange for a review? If there's no contract involved, if there's no exchange of benefits, you don't have to do it. Can the author get mad and not give you any more free books? Yeah, she can. But she also needs to know that readers are not obligated to do . . . anything. They don't even have to read it.
But by the same token, don't be afraid to say you really liked a book that others found fault with. Some of us are really picky readers. Maybe it's because some of us are also authors and we do tend to look for and see the technical problems more often and more easily than the casual reader. Maybe some of us are just jealous meanies out to destroy some poor writer's career. (I highly doubt that, but it's possible.) But maybe readers just didn't like that book and you did. If you liked the book everyone else hated, that's okay, too. Something in that book touched you, and that's a good thing. You don't know how many other readers out there might be just as touched by that element, that style, that setting, that. . . . whatever.
And yes, there are readers and reviewers who love everything they read, who never have a criticism, who dole out 5-star ratings like candy corn at Halloween. Are they being dishonest? I don't know. Maybe they really do love everything they read in all genres and all styles. Maybe they really do. Maybe their mothers taught them if you can't say something nice, don't say anything at all and they took it to heart. Maybe they're just uncritical readers. Maybe they want a lot of free books to sell on eBay. Maybe they're greedy for fame as a top reviewer on Amazon or Goodreads. Maybe they're frustrated writers who are living vicariously. Maybe they just want to be loved.
But as far as I know, they have a right to do that, too. Readers are savvy people, and they'll figure out which reviewers to pay attention to and which to ignore. Remember that: Readers are savvy people. They'll quickly figure out if you're reviewing just for the sake of reviewing or if you're a good analyst whose judgment they're going to trust when making their own book buying decisions.
Oh, to be sure, there may be guidelines set up by the place you're posting your review, and those have to be adhered to because the guys who provide the space do get to set the rules. But it's still your opinion and your review.
Go for it!