A textbook “tells” you nothing. You must ask it questions in your mind as you read. Get questions from your instructor, from the end of a chapter, or by changing the headings from statements to questions (i.e., “Causes of the Civil War” to “What causes led to the Civil War?”).
The author most likely worked from an outline when the book was written. It is your job to distinguish the original main points. The system is: WholePartWhole
Briefly outline the reading assignment on paper in your own words. Underline the most important elements.
If there’s a summary, read it first, then keep the point that it emphasizes in mind as you read the assignment. Notice the paragraph headings. In fact, scan the chapter and read the paragraph headings before you read the text.
Check for new vocabulary. Learn to use the words.
Lecture notes can be effective study aids. To take notes well, you must be able to select the main points being made and express them in your own words or, at least, condense the lecturer’s words to insure a short, clear understanding of what’s being said.
Review your notes often. Just before class is a good time because it helps connect the lecture you’ve heard with what you are about to hear. Look at your notes frequently enough to let you see how each lecture relates to the lectures before it and to the larger course units.
Take notes in an organized way to make their meaning clear.
You can speed up and simplify your note-taking by staying aware of several “easy-to-fall-into” traps.