Research, at its heart, is a process of asking questions and seeking answers - remember this as you embark on reading a scientific paper. Scientific research is shared in a standardized and highly structured format - the scientific research paper. While it may seem daunting at first, ultimately this format is a tool to help you efficiently make sense of the work being presented. Familiarize yourself with this structure (abstract, introduction, methods, results, discussion) and use it to your advantage to digest the content therein. Although there is no one right or wrong way to read a paper, below I walk you through a system I recommend. I encourage you to explore the links below, google other advice, and ultimately devise your own approach.
1. Find the question being asked
Remembering that research is a process of asking and answering questions, when you approach a scientific research article, your first step should be to try to identify what question the researchers are asking of the world. This is often spelled out in the final stages of the introduction - in the paragraph or two preceding the methods. After glancing over the rest of the paper, this should be your first stop.
2. Identify what the experiment measures
Often, in this same section, and typically in the same paragraph, researches will clarify what they will measure in order to answer their question. After identifying the question being asked, identify exactly what they have decided to measure in order to answer the question they've posed. For example, to measure plant growth with they take a measurement of biomass or count the number of leaves, or both.
3. Sit down with the introduction
Think of the introduction like an essay that makes an argument for why measuring what the researchers propose they will measure will help them answer the question they are asking of the world. Try to absorb their main points. Along they way, the researchers will likely also make a brief argument for why it's important to try to answer the question in the first place - this is typically done in the opening paragraph, and sometimes even the opening sentence. Try to just take it in here, later you can decide if they have convinced you.
4. Skim the methods
Get a sense of how exactly the measurements were collected, but don't get bogged down here now. You can always return later, as pertinent.
5. Review key results
Remembering what was to be measured, now read the headings in the results, the graphs, and/or the first sentences of each paragraph. These places should succinctly reveal the findings. Once you've taken in the main outcomes, you can revisit the remainder of the results now, or later, should you feel compelled to dig into the details.
6. Decide if the measurements really do help answer the question posed
Now sit down with the discussion. The opening will typically briefly recap the main finding from the study and then begin to assess how well those findings speak to the original question posed. It's worth spending a bit of time here to take in the researchers' analysis of their work. This is where the researchers will do their best to answer to the question they posed, share what might have gone wrong, or relate the knowledge gained from their work.
7. Revisit sections of interest and/or read abstract
As you like, return to any of the sections above to dive deeper into the researchers process or revisit their ideas and arguments. It's also a good time to take a moment to read the abstract to see how the researchers have encapsulated their work for distribution.
8. Acquaint yourself with the authors and their research
At anytime in this process, consider googling the names of the authors of this paper to get to know their research backgrounds and institutional affiliations. While this is not necessary to reading the paper itself, it's a step towards familiarizing yourself with the scholarly community with which you are engaging. It also humanizes the process. Scientific research is deliberately shared in a very objective style. It's important to remember that science is a human endeavor, through which we work to better understand the word we live in.