It rather depends on the article. For archaeology, there's usually a few sections you can count on being there. For one about burials at an Inca site it'll look like this:

• Introduction/Abstract: There's burials at this site. When were they from?

• Background Information, Summary of Past Research: This is what other people have said about burials before and during Inca control in this region

• Presentation of specific information: This is what our site looks like.

• Methodology: This is how we recorded and selected information to analyze.

• Results (usually the meat of the article): Here's what the burials at this site are like.

• Conclusions: This is when we think the burials are from, this is what that tells us, this is what we need to research next.

Which part I read really depends on what I already know. Articles are usually predictable enough that I can use headings or first sentence to pick and choose paragraphs to skip, skim, or read legitimately. I'm not too familiar with Inca burials, but I'm very knowledgable about earlier ones in the Andes, so I might read the majority of this article. I'd probably skim the section on results though, since that will contain a lot of details I don't need to know. I'll look at pictures and diagrams and charts to get some idea of the topic, but I won't make much sense of them without the author's conclusion. I might focus also on the methodology so that I can compare my techniques with theirs.

On the other hand, I recently read an article about GIS analysis of Archaic settlement distribution on a Greek island. I know very little about pre-Classic Greece beyond the two weeks I studied it in a Classics course two years ago. But I have recently done GIS analysis of settlement distribution in the Andes. I could skip the two pages of methodology and the entire article made sense.

Lastly, when the article is closely related to my studies (i.e. the author has visited my site and I've run into him in various cafes and discussed archaeology stuff), I can skip just about everything but the results and conclusions. I don't care much about the exact arragnement of stones in an Inca burial 1000 years after my site was abandoned, but that's rather important when it's the site across the valley.

For monographs (single author books):

I know the narrative for my field very well, so when I pick up a book I haven't read, I'm mostly interested in seeing what the author is arguing, what methods s/he is using to make the argument, and what kinds of evidence are used to support the argument / are conspicuously absent.

If I want to get a sense of the whole book, I'll read the intro carefully and note the arguments the author says s/he'll be making. This tells me what's going to happen. Then I read the conclusion, and see how those arguments worked out in the end. I know know what the author is arguing, and perhaps how they say they're going to make and support that argument. Then I'll flip through each chapter and see if the author actually does what s/he sid s/he was going to do (often, authors don't). I'll also look at who the author is citing to see what evidence and arguments s/he is engaging.

My favorite books are clearly organized, and you can follow the same method within each chapter that you use for the book as a whole. Read the chapter's intro, conclusion, and skim section headings and topic sentences. Don't read every word - just try to answer the questions: what is the argument, how is it being made, what is the evidence, is it persuasive? If the books is clearly organized, you can get through it in a few hours.

Of course, some academics are allergic to topic sentences and clear organization. Their books are harder (for me) to skim.

That's when I want to read an entire book. Often, however, I'm only interested in a specific chapter. If that's the case, I'll read the chapter carefully, but will also read the intro, conclusion, and skim the other chapters so I know how that one chapter fits into the larger argument of the book.

Edited volumes (collections of individual articles) are harder for me to push through quickly; I usually end up reading the intro chapter, and then skimming individual chapters that look interesting (using the intro, conclusion, middle approach outlined above), and reading them in their entirety if they seem good while I'm skimming.

For journal articles, the trick is to figure out the scripts authors in your sub-discipline follow. Archaeology articles usually follow a clear script, as /u/CommodoreCoCo says (there's sometimes also a theory section between the background and specific data sections, if the author is so inclined). Other disciplines are similar - you get a feel for it the more articles you read within the subject area.

Ultimately, though (in my experience at least), you have to have a lot of experience to really race through academic writing. Most historians do similar things, and within each field the similarities are even stronger. Once you've read 200 books and a few hundred articles, you'll be able to get through books very quickly. But when you're new to a topic, it can be slow going at first, because you're still learning all the names, dates, and details of the narrative. By the end of my qualifying exams (reading 150 books for my PhD), I could read a book in 3 hours. But when I started grad school, I had to spend days on a book to know what was going on. That's a normal experience.

My history professor's advice (specifically for historical writing, whether book or article): the structure tends to be a paragraph with a finding or claim, followed by many many pages of supporting evidence and discussion, primary source codes and quotes from prior works on the subject... The former tends to be articulated at the beginnings of chapters or sections, and re-hashed at their ends, the latter forms the body of the chapter. Basically, if you are hurting for time, read the thesis expounded at the beginning, then skip the evidence unless you want to dive in deep.

As a time-pressured student, I would suggest skimming through a book: understand core arguments and get good quotes. I've found that in terms of specific information, articles from journals like past and present have really good case studies and lots of detail on a specific topic; they're usually like 30 pages long so reading them in full isn't so bad.

This means that you can churn out an essay with like 6-7 books and 5 or so articles in like 4 days. It's probably not the best way to do it to truly understand the topic, but it's quick and useful if you have deadlines every week