You can either buy the books permanently, or rent them for a time frame that is user specified. You can highlight and take notes.
Amazon.com: Kindle Textbook Rental
However, it appears that only one of my books this semester is available, and only to buy, and not that much cheaper.....
I may pick up a kindle soon, and hope I can go that route in the near future. I have looked at iPads, but with the nearly new macbook, it seems a bit of a waste.
Oh and I am done with science related classes.....