I actually prayed to God that I remain alive at least long enough to read the last installment of J. K. Rowling's wizarding adventure. Sure, it might be a little embarrassing to confess that, but the sentiment is indicative of a morbid truth: I will not be able to read everything I'd like to before I'm called to eternal life. There just aren't enough hours in an entire lifetime to read everything. If you're a bookworm like me, that's reason enough to get sweaty palms and nausea. Which means, whatever I pick to read better be worth my time.
In my youth, I'd read books all the way through to the end, even if they sucked; not anymore. There are many great stories out there better deserving of my time and imagination. Granted, there are very few books I've actually stopped reading (mostly self-help, Christian spirituality tomes), but the satisfaction of knowing I can move on to something more worthwhile is priceless. The problem is how can I know something is worthwhile before I read it?
If you happen to enjoy a book from a particular author, chances are you'd probably enjoy--in different degrees--other books written by the same person. This is perhaps the most sure way of selecting a good book. It's like going to see a movie because one of your favorite actresses is in it. Sure, some of her movies will be better than others, but even if you pick a bad movie, you can always enjoy her skills. But that's not enough. Actors and actresses can only make so many movies a year--not nearly as many as you'd like to see. So, you try to branch out, maybe watch a movie someone recommended.
Watching a movie a friend recommended is like buying a book because you read a review: some recommendations are great and some are not so great. It's hard to gauge. Personally, if a friend tells me I should read a particular book, I do. I figure that if they go through the trouble of verbally encouraging me to read a book, it must be good. But I don't give book reviews the same weight. That's not because I don't think they're worth it.
I judge books by their covers all the time, and if not for well-written reviews, I'd be duped every time. Book reviews have helped me from throwing away money on an underserved volume. The other side of the coin is equally valuable. I've purchased books because they've received great reviews. Yet, because I don't take the time to get to know and trust one particular reviewer, it usually takes a group of collective reviews to help me make up my mind.
This gives me renewed respect for good reviewers. Good reviewers don't tell you whether or not you should read a book. Instead, they describe enough of the characters and plot to give you and idea of what the book is about, and present its major strengths and weaknesses. If they did their job right, you should be able to make the decision to purchase on your own.