Educators recommend the formula SO3R when reading a material. This means survey, wuestion, read, recite and review. Get photographic idea of pages first by recognizing the headings or titles. This surveying or skimming. As  you survey or skim, questions will come to mind naturally. Jot these questions down first. Then you read at your natural speed and grasp the meaning of the topic. Many students find that reciting the meaning of the topic understand and memorize better. Others find reciting unnecessary and disturbing to their memory work. Do whatever applies in your case.