After a thorough pre-reading, you should have an inkling of what the book or article is about, what the author’s general conclusions are, and what method the author uses to reach those conclusions.
The next step is to decide at what level you will engage the work.
Can you learn all you need to by spending more time skimming through the work’s major sections, as you have the introduction and conclusion? If not, you may need to devote time to a closer reading of the work in part or in whole. This decision will determine what step you take next.
Other "Better Reading" topics:
Guide to Better Reading Home
Becoming a Demanding Reader Home