Reading at degree level needs to be productive; productive reading is usually known as ACTIVE READING. You can make sure that you don't waste time by thinking about exactly why you are reading and which approach to take for different purposes.
There are several useful approaches to reading, none of which includes reading a whole book from end to end as you might read a novel. One well known and successful approach is SQ3R:
Skim-read any Preface or Introduction; this will often give a brief summary of the contents. Look at chapter headings and chapter summaries and conclusions. Check the index for specific references. Consider the reputation of the author. Note the date of publication. Note any useful figures/diagrams. Look at the bibliography (a short one might indicate a rather superficial approach). Select a useful section to read.
What is the main idea or theory? What is the author’s argument and/or perspective? What evidence is being offered? Is it valid and up to date? How does the argument compare with other reading?
Read a section at a time, at a speed that allows you to think. Engage with the material. Look for topic sentences and summarising statements to get an overall sense of the argument. Look out for useful ‘key quotes’ and see how illustrative examples support the argument.
Re-call the main ‘note-worthy’ points, by quickly re-reading if necessary. Make notes that capture the main ideas in your own words. If there is a supporting ‘key quote’ so much the better. Clearly identify it as a quotation; copy it accurately; note the page number so that you can reference it if you use it.
Review your own notes when you reach the end of the chapter/article. Do they make sense? Are you confident you understand the argument made by the author?
For tips on reading at this level, watch: https://www.youtube.com/watch?v=fam4P0x-VAc
For tips on scanning, watch https://www.youtube.com/watch?v=Dy69pPGDeIg
For more on reading, go to: Reading Skills