I shop by genre- I go into the Fantasy section at B&N and pick whatever looks good. I’m almost exclusively a fantasy reader.
How do you pick your books?
I judge them by their cover.
I judge them by their cover and no I’m not kidding. I like to go to used book shops and browse. Usually I read the first couple of pages of the one that catch my eye and then I change my mind about a hundred times before I actually make up my mind.
I also judge a book by it’s cover. Then I open the book anywhere (usually about half way thru) and start reading. If it doesn’t grab me after a couple paragraphs, I don’t buy it. If I find myself on a second or third page before I stop reading, I buy it. A good book can grab me on any page and pull me in. It’s never failed me.
I browse. However, I also use the Amazon recommendations, but not necessarily on Amazon. I’ve received some great book recommendations here, and from friends, and from various booksellers. The comic shop owner is particularly good at giving me advice for both graphic novels and SF/fantasy books, though he only sells books with game tie-ins. Sometimes I’ll strike up a conversation with another customer in a bookstore, and we swap favorites.
FTR, I read SF, fantasy, mystery, general fiction, and nonfiction.
I love going into a place like ‘The Sleuth of Baker Street’ and cornering someone, giving them a list of 3 or 4 authors I’ve read and liked and asking them to recommend something in that vein.
A website that I adore - Fantastic Fiction is invaluable to me because I have a fetish for reading an author’s works in order of publication.
I almost never read the back or inside cover blurbs - I once did that for a Raymond Chandler novel. The excerpt they chose for the inside cover was a quotation from a passage two pages from the end. Up til then, I was always aware of those quotations until I’d read past them - in this case, I was puzzled that I’d missed it until about 2/3 of the way through, where I realized that the only way that scene could happen was the solution to the entire mystery. Could have throttled an editor that day.
Recommendations from trusted friends and family, almost exclusively.
I avoid them too, but not for the same reason as you. Jacket blurbs are about as useful as a Harriet Klausner review. Oh wait. They’re the same thing. 
I haven’t been inside a bookstore in years. I’ll get recommendations here or at SFF World and then head to Amazon to read a few pages. If the Look Inside feature isn’t enabled, I don’t buy the book.
For fiction - almost exclusively recommendations from family and friends. Non-fiction - recommendations and online searches of specific areas of interest.
My publisher says that no book can end up selling well other than through word of mouth recommendation. I am involved in radio interviews, and the press reviews, for my book. Yet none of you (including my top-of-my-head response) have mentioned them as having any impact on your buying. Sobering!
Just last week I picked up a copy of The Time Traveler’s Wife.
Why? Well, I was surfing the 'net and I saw an article about a 10th Anniversary screening/reunion of “Office Space”. One of the comments noted that Ron “the liberal douchebag” (?) Livingston didn’t attend. That got me wondering about what Ron might be up to these days. A few clicks, and I discovered that he’s playing Gomez in the movie of Audrey Niffenegger’s popular novel. The story looked interesting, so I decided to check it out.
If it’s a factual book I’ll read the chapter headings, sometimes have a goo at the index.
If it’s a novel I’ll read the blurb.
I also judge books by their covers. I used to go to the library and just browse and grab. Now that I’ve established my tastes for the most part, it’s pretty self-sustaining. One book seems to lead to another and another and… my to-read list is over 500 now. Eek.
I try to go off reccomendations from friends, family, and a variety of online sources. Sometimes if I’m bored or really want something to read I’ll just go to the rack and grab something that looks decent. (Last time worked out well for me - ended up with Greg Keye’s Kingdom of Thorne and Bone series).
See, when I hear “word of mouth”, I think reader’s mouth, not publicists or the press, or even the author.
But I have checked out books because of radio interviews, mostly from NPR’s Maureen Corrigan, and occasionally when the local NPR station interviews an author. (I was late for work the day they interviewed Joe Hill.)
Another resource I use but forgot to mention is Bookmarks Magazine.
I don’t trust the mainstream press though, not since Time and Newsweek raved about *The Historian[/]. (I still think Kostova was boinking an editor.)
Recommendations from friends and family (ones with similar tastes, anyway. I’m going to pass on Twilight, thanks). Especially if multiple people independantly suggest the same book (I may be picking up A Walk in the Woods in the near future).
Amazon recommendations. I spend a lot of time clicking “not interested,” but I’ve found some real gems in books I wouldn’t have considered or even heard of.
I think the Barnes & Noble website used to have a pretty good search feature, so you could browse through all kinds of genres and subgenres. Haven’t tried in a while, but I remember it not being that useful last time I tried it. Had some great results from it way back when, though.
When I’m not picking up yet another Discworld novel, or hunting for more Lovecraft stories I haven’t read, I always gravitate toward toward any section marked “Classics” or something like that. You’ll then find me, half an hour later, sitting amongst a pile of books from all kinds of different authors I always intended to read, trying to figure out how many I can afford before cutting food out of my monthly budget.
If I’m looking for a book that was originally written in another language, I try to research exactly which translation seems the best for me, and note the ISBN if necessary.
I never read the blurbs, for the exact same reason as Le Ministre de l’au-delà (I also skim/skip reviews and summaries that start revealing too much of the plot). And like An Gadaí, I’ll read through the table of contents if I’m looking at a reference book of some kind, and skim through the sections I’m most interested in.
Lastly, if I’m at a library sale of some sort, I turn into a Kid in a Candy Store, grabbing anything within arm’s reach (the older it looks, the better), and reading a few pages. I usually end up with quite a few books, that way…
I get a few recommendations here and a few from friends and family but I find the vast majority of the books I read by browsing the library and used book stores. I get a vague idea of what I’m in the mood for, and then when it comes time to pick a specific book, I’m another who literally judges books by their cover. Hey, some sayings are bullshit.
I’m another one who chooses what he reads by the cover. I’ll also use suggestions from the Dope (we’re great about suggesting stuff in “uncommon” subgenres), but as a librarian I also get all the pre-release blurbs about upcoming books and I fill out my “to read” pile with a lot of books that aren’t scheduled for release for another few months or so. Then I have to remember they’ve actually been released.
I gather from recommendation threads, Top-whatever lists, friends’ recommendations, and Amazon suggestions. When a book has gotten my interest, I glance at its Amazon rating, summary, and sometimes comments, then put it on my “library” wishlist at Amazon, where it will sit on a queue til I get around to requesting it from the library. If I really like it after I read it, I put it on my “to buy” Amazon wishlist. Otherwise, crossed off the list.
So it goes.
I’m always on the lookout for suggestions, here and on goodreads.com, and from friends and family. I read mostly historical fiction and science fiction but I’m open to almost any genre.
I love to browse, especially in used bookstores, but I’m always looking for an author or title that I recognize. I carry a wishlist in my purse for such occasions. I rarely pick up a book cold, although one of the very few I did choose at random, many years ago, was Dan Simmons’ fantastic Hyperion.
Mainly by the blurbs. If a writer I like or publication I respect recommends a book, I’ll check it out.