Let me make it clear that just because the title reads "how to..." doesn't mean I consider myself some sort of an expert on writing book reviews. In reality, I am not even close to mastering it. I am writing this post merely to express what I consider to be a good book review and to state a couple of things (literally) that I try to keep in mind while writing book reviews; not to mention, get your views on the topic!
1. Avoid Spoilers! It took me a long time to learn how to summarize books without accidentally including spoilers. Personally, finding out the suspense or a plot twist doesn't really affect my reading experience much. But I know people who are entirely capable of holding life-long grudges because you accidentally told them who dies at the end of Harry Potter.
There is one thing related to this that irritates me very much, and that is a spoiler alert! Something written in the background colour, which can't be read unless it is highlighted; or in some cases, the words SPOILER ALERT written in bold block letters (followed by a thousand exclamation points) and then the whole plot and twists and everything that should have been withheld spilled out. Such a review just seems very amateur-ish (not that reviewing books is my profession.) Also, anything that comes with a spoiler-alert is probably unnecessary. A good summary, for me, is one that can make a person want to read the book and at the same time, keep much of the plot a mystery.
2. Be impartial; that's the first rule of writing a review, at least for me. If you don't like something, don't be afraid to say it. I understand that every writer puts a lot of effort in his book; but you can't let that affect your review!
That being said, I don't like reviews that are too harsh, especially in a vague way. You can't just say "That book is horrible" or "You shouldn't read it!" or "It shouldn't have been published" or simply "It sucks" and expect that to suffice. There has to be a reason behind your not liking something, and it is your job as a reviewer to discover that reason and along with that, a reasonable way to express it.
While we're on the topic of being impartial, "It's awesome" isn't a sufficient reason to recommend a book either (something that I am still working on!)
What about you? What are your expectations from a book reviewer, what sort of reviews do you like and what do you consider to be a good book review??
P.S. - Apparently, today is World Book Day. Not that I need to reserve just a day to celebrate my love for books; nevertheless wish you a Happy Book Day and happy reading!