If ALL your classes required this it would be a significant problem, but fortunately different classes require different amounts.

I discovered this handy little trick as an undergraduate of getting the reading lists and the textbooks as soon as they came out. That way... I could actually get the significant majority of the reading read (first pass anyway) before class started. I found I was much more able to retain the information on the second pass through. Sorry, this probably doesn't help terribly much now, but I guess it might help you plan ahead for the spring semester or next year.