Attending college/university usually requires quite a bit of reading. To manage your time effectively, you have to formulate a strategy for reading. This is easier said than done - I know!
However, you can piggyback on the many students' experiences that have been where you are now.
All roads lead to Rome.
There are different roads to take about this, but let's split it up into three main approaches:
Maybe you learn things best by experiencing them visually? Try creating mindmaps, flowcharts, and drawing on a piece of paper next to you. This way, you can trigger your brain into focusing on the essence of what you are reading.
Talk about it
Talk with your fellow students about it! Believe it or not, taking the time to convey a topic and discuss it with your peers can actually lead to less time wasted in the long run - and increasing your comprehension of a subject. Go for summarizing what you have just read, and see what other people in your group focused on.
Write it down
Buy a notebook dedicated to a specific course or bring some paper. Asking yourself questions and writing down the points you find relevant can ease your reading. Put an Asterix next to the most critical issues. If you are the kind of student who actively uses your textbooks, you can also use the margins for noting important points and highlighting with a colored pen.
There is no single right way.
Try out a different set of things, and see what is working for you. Remember that there is no single right way to study, so it is all about finding a strategy that works for you - and sticking to it.
Finally, I just wanted to pass on some of the resources you can use for improving your reading techniques: