Harmony Central is OK if it's a model that's been reviewed by lots of people. Then you can skim the reviews to see what people say about their other gear, musical preferences, age(!) etc and find those whose views seem to be most "in tune" with your own.
yeah, pretty much. Take them with a pinch of salt, and if the article sounds like it was written by an idiot then it probably was. But if you wade through 20 reviews you might find a good one, as long as you're extremely sceptical about everything you read.
I think the big problem about reviews is that it polarises everything; unless you're the type of person who likes writing reviews, two things are likely to act as an incentive to make you actually get round to writing one- feeling like you've got a kickass deal and wanting to let everyone know, and feeling like you bought a cr@ppy product and/or got ripped off in which case you want to warn others to make yourself feel a bit better, like you got your own back. You're not likely to bother if the gear is decent but unspectacular, kind of thing.
Oh, and the third thing which can make people write reviews, showing off new gear: the person writes a review the same day (probably the same hour) as getting the new piece of kit. Those reviews are useless too.
EDIT: it also depends very much on what kit is being reviewed. if you're reading a review of beginner kit, there's a good chance a lot of those reviews are being written by beginners. If you're reading a review of a more obscure piece of kit, there's a better chance the review will be sensible.
of course, it's not foolproof.