How to Read a Journal Article

First, find a journal article, for example from the open access journal PLoS. I picked this article about mutational mapping in yeast. Articles offered in journals usually come as both a printable pdf or a full html version. There can also be supplementary material published online as articles become more complex but space to print them remains the same. In my example we have the abstract at the top, this is what is given away for free, it offers a summary of the article and results.

Introduction: A good place to start, learn the background info and where the author states what questions their paper hopes to resolve.

Materials and Methods: In my example these are at the bottom of the article. They are full of details that are useful if you are trying to do the experiments themselves or you want to compare someone else's experimental method with your own. Generally I wouldn't recommend reading them until you actually need instructions on how to do something.

Results: These go step by step over what the experimenter did and what they learned. This also contains all the figures and tables that were developed throughout the experiments.

Discussion/Conclusion: The author will reiterate the purpose of the experiment and what was learned. They then go on for more flights of fancy and speculate what this might mean as well as suggest future experiments.

So a suggestion for reading a paper: Abstract -> Introduction -> Discussion -> Probably read Results -> If needed some day come back for Materials and Methods.

Finally, a note about authorship - as a general rule for biology papers the first author did the bulk of the work, the middle authors were corresponding authors or supervisors of the corresponding authors and the final author is the supervisor. The supervisor will have the lab whose research focuses on a general topic and there will be years of work done in this area under that supervisor. The first authors tend to be grad students and postdocs who will write about a topic for a while till they graduate/move on to a new supervisor. There are exceptions of course, this is just a general guideline.