It depends on the class/subject matter.
I wasn't expecting this, but I actually find it useful to read my Pharmacology chapters. I'm not sure if it's because I enjoy pharm, or because the book is good, but I find that reading the chapters through at least once was pretty helpful. So, for that, I do make the time to read the book and compare with my teachers notes. My pharm book is to the point, so the chapters are short and informative. I find a lot of textbooks have a LOT of extra fluff.
Patho? Hopeless. We have also covered 30 chapters and I am only 1.5 months in to my first semester. I'm in an ABSN, if that makes any difference. Maybe it's the book, but I don't have time to read it word for word. I DO, however, go back and re read any concepts that I am very unclear on. My prof is a godsend in that he gives us wonderful notes. We have to complete weekly discussion boards that require us to read through important topics in the book, so I DO have to do it then.
Fundies? Sometimes. The book is enormous and often has a lot of fluff. Again, this is one where I go back and re read if I am having issues. A lot of times our prof for this doesn't teach on a topic that will be on the test, so it doesn't leave me a choice.
It depends. You might find that you will have different ways of studying for different classes and different subject matter within the same class. In pharm, I have used a different method for quite literally every module. I guess my preferences just change!
Edit: If I were to read ALL readings every single week, it would be over 10 chapters of DENSE material. I think I tried this my first week, but I found that it just took too much time. FWIW, I am a speed reader and if anyone could find time, it would have been me. Do I want to? Yes. It just can't be my priority because my priority is completing assignments on time. Thankfully, my professors are pretty realistic, but one or two of them isn't and that's kind of a bummer, but I learn who those profs are early on and how to do well in their classes.