The etiquette of book reviews

I haven't had a book review anywhere except on this blog of mine for ages, so I was wondering recently if there were any suitable places to consider. A quick search and I'd found a few likely contenders, but I'd also crossed off a couple due to what I saw as bias.

If a website or magazine only allows its reviewers to go as low as 'good' in their ratings (as opposed to 'excellent', 'life-changing' etc), that can go one of two ways. Either you follow the old 'if you can't say something nice, don't say anything at all' (leaving the reader to assume that if there's no mention of a book it must be rubbish, when in fact it could just be that no-one's reviewed it yet), or if you're reviewing to get your name out there, you might be tempted to put a positive spin on a poor book (or out and out lie about it). Neither approach seems particularly helpful to the reader, which surely is the point of the review.

I've been reading Private Eye on and off for the last 17 years, and I know there are plenty of reviews out there written by friends, relatives, colleagues etc of the author which say overwhelmingly good things about a book (deserved or not) in order to pay back or call in a favour, or to drum up trade. I also know that any book reviewed in Private Eye itself is likely to be there to allow the reviewer to exercise wit and venom in tearing it apart (so if that doesn't happen, I tend to assume the book's a superlative effort, though maybe it's just been written by a friend, relative or colleague of the Eye's reviewer...), not so much a book review as a catty erudition article.

What a review should be (in my opinion) is as fair an assessment as possible by someone who would generally read a book of that sort. I wouldn't review a romance novel because I'd be prejudiced against it from the start and know nothing of the conventions or expectations of the genre; I wouldn't ask a literary snob to review a science fiction novel for similar reasons. If my dad says the latest Robert Rankin's lacklustre I'll take notice of him, if my mum (assuming she could force herself to read it all) said the same thing I wouldn't care because I know it's not her kind of thing. While I don't in general want to read or write negative reviews, I'd want to be warned by someone else who's enjoyed a particular author's work in the past that their latest offering is below par, and I'd want to be able to say 'normally I like this kind of thing but the characters in this book are just wooden'. Constructive criticism is part of a writer's improvement process, and if I was disappointing my previous readers, I'd want to know.