Don't try to tackle assigned readings in textbooks or online as you would a novel or Facebook post. Instead, take the following approach to each chapter or individual reading assignment:
Read the Introduction and the Summary.

  Consider this a preview of the topics you will encounter. They also provide an overview of what you are expected to understand by chapter's end.

Ask questions about the reading and try to answer them as you go along. Turn the topics mentioned in the Introduction into questions and refer to them as you go along.

Tip: Jot these questions down in the margins of the book, in a notebook you keep on readings, a file on your computer, or on stickies placed in appropriate sections within the chapter so they are handy as references. You should find the answers as you progress through the reading. If not, read the section again looking for what you missed. If you have difficulty understanding anything from the reading, be sure to make a note of it and ask for clarification during lecture or recitation.

Look for visual clues. Bold print, underlining, bullets, font size, color, and type placement are often used to draw your attention to key principles and concepts. Illustrations, charts, diagrams, and their captions are equally important. For example, Biology textbooks tend to be illustrated colorfully; the photos and diagrams often can clarify concepts better than the text itself.

Recall and Recite. After each section of required reading (following the steps above), stop for a minute. Close the textbook and do not look at your notes. Ask yourself the questions you created after reading the preview. If you cannot answer them correctly or completely, reread the section and try again.

Review. Reread the introduction and summary sections. Do your questions, and, most importantly, the answers come immediately to mind? They should. If they don't, review the section again and consider taking more complete notes.

Source:web.mit.edu (Collected by ESC)