Is there a better method of reading from textbooks and taking notes without spending an hour on each chapter?

Can't just skim because teachers like to pick up specific information.

And also, what have you found aids in retention of that specific material?

I think it really depends on the course.

For some courses (humanities, etc) I would basically skim and take notes of the things that I didn't understand on a separate sheet.

After I finish the chapter, I would read these notes carefully and read the chapter again with those items in mind.

You would think it would make more sense to just slow down and actually understand those concepts, but in many cases it becomes clear later in the chapter anyway and time used to understand it on the first pass would be wasted.

Also, the professor almost always drops hints about the random stuff you will be tested on. With experience you learn to pull these out of the lecture.

i just read, man. try to get so into it like it was a novel and you don't care about how long it takes to read. although i usually put off reading until the day before, or if i'm lucky, two days before the test. then the day of while the information is still fresh in my mind, i review some of the key parts or read the vocab words/chapter summary. on a multiple choice test i find it pretty easy to recall obscure facts by looking at the possible answers and comparing them to the text book, selecting what sounds like what i remember reading.

other than that, no tricks.

as far as retention...shiiiiiit. you mean retention for the test or retention forever? cause you're bound to forget stuff sooner or later. more likely sooner if you then go on to study things in other classes next semester.