When you read a book do you read every word and try to remember most of the details or just skim over the book to get a general idea of the plot? I personally am the former.
I don’t think a single person on this forum just skims through a book that they’re seriously attempting to read.
The only time I skim is when a book isn’t engaging me. If I find myself skimming, I usually put the book down. Forever. 
I skimmed Twilight. I wouldn’t have bothered with it at all, but a good friend said I had to read it.
It really depends on the book.
Some books, as AuntiePam, points out, just don’t engage. Or sometimes I’m reading them in an environment conductive to just wanting to read but that isn’t great for concentration, like being on an airplane.
If a book is good enough, I’ll read it more than once, and in some sessions I’l lread carefully and in others skim.
If you want to read like that in the future, I can save you some time. On one side of a book, there’s a cover. On the other side, there’s another cover.
There! You’ve just read every single book in the library and are no longer able to tell the difference between Nancy Drew and James Joyce.
I agree, with the skimming. If I lose interest, the book goes down. I can lose interest fairly quickly, too.
It depends on the book. Some books ought to be read quickly, others slowly.
While I usually do read every word, I don’t necessarily pay attention at the individual-word level. With a pop thriller like The Da Vinci Code, I’ll read quickly: I’ll want to pay enough attention that I don’t miss any clues or plot points, but I certainly won’t try to savor the language. If a book has interesting parts and boring parts, I may try to get through the boring parts as quickly as possible without missing anything important, while with the interesting parts I won’t even have to pay attention to how quickly or carefully I’m reading; it’ll just flow naturally.
The same goes for non-fiction. Sometimes I will skim, and just try to get a general idea of what the author is trying to say, because some books just have a few points to make, but they’re padded out with extra verbiage. Other non-fiction books have a lot to say, a lot of information or ideas to offer or a closely reasoned argument, and I’ll read those more slowly and carefully.
For starters, I read as fast as I talk. That’s comfortable for me, especially if the book is interesting. I savor it.
If, in parts, it’s getting slow or dull, I might start speed-reading, which I find annoying to do, but I do end up getting the gist, and get through it much faster. But then will slow back down once I finish that segment or chapter.
If it’s just plain bad, or not interesting at all, I’ll just stop reading it. Who has the time?
If I start skimming, then I’m not enjoying the book and it won’t be long before I put it down altogether.
Unless I’m re-reading. Sometimes I’ll skim over the slower parts of a familiar book to get to the good stuff, since I already know the details of the plot.
The only time I ever skim is if I’m re-reading a book I’ve already read a few times. I know the overall story well enough that I can just skip over the less interesting parts.
I read every single word with my “inner voice,” at exactly the same speed as my speaking voice. This does not, however, imply that I remember what I’ve read any better than anyone else.
It depends on the book and the writer, and more importantly on the section of the book. For instance, with Tom Clancy, there were chapters I would read every word, and there were infodumps I would barely skim. There are some series where I like some of the books and don’t care for others, but I still want to be able to follow what went on, so I will skim the books it turns out I don’t like.
As with many folks, for me it depends. There are wordsmiths out there that will have me reading every word, just for the pleasure of the language, regardless of the storyline. But they are rare, and I have in fact gone back to make myself re-read a paragraph or page I have skipped because it actually WAS paramount to the storyline. Because I do tend to skip over parts of books that bore me, which include lengthy descriptions of the scenery and battle or fight scenes that last longer than a paragraph or two. Sorry, writers; I know it takes time to craft those scenes, but unless there’s something intrinsic to the plot that occurs during those fights, develops character or something <like the final fight scene between Achilles and Hector in “Troy”> then really, all I want to know is who won. Not sure why, as I do appreciate philosophical novels and all. It doesn’t have to be ALL dialogue, but something that is no dialogue at all is likely to bore me, I admit.
I read every word with two exceptions: I skip over the mushly love scenes and I skip over descriptions of what goes on on a boat to get from point A to point B.
I skip songs and poems, almost without fail.