Once you find one good article, you can use it to find more useful information. There are several different ways to do this. Below is an image of a typical PDF article from a database journal.
Looking for other works by the author is a good way to find related content. Usually authors write multiple articles on a similar topic. Similarly, abstracts contain many key words which maybe useful to you. They are located in different areas in documents but usually near the top. By skimming the abstract and looking for key terms, you can do another search on the same subject with those terms.
The works cited list of any document that contains one is a great place to find or "mine" for additional information. Below is a part of the works cited for a document. You can copy and paste the title of the article into the title field of the advanced search options to see access options. You can then repeat the process with the new source.
Sometimes, within a document there are references or footnotes. These are usually represented by numbers near what they are referencing.
When you see one of these numbers near a point you would like to investigate further, look to the bottom of the page, and you will see a source or a further explanation of where the information originated.