APA Referencing is a referencing format that is used in many universities and schools. It basically outlines the author, when it was first published, it’s access date and it’s URL
For example, wikipedia.org
It was written by John Henley(not real author)
It was published in 2001 and was last updated on 18/05/16
Here is the finished product
HENLEY, J.
Wikipedia
In-text: (Henley, 2016)
Your Bibliography: Henley, J. (2016). Wikipedia. [online] Wikipedia.org. Available at: http://Wikipedia.org [Accessed 18 May 2016].
A reliable website is citethisforme.com
Some tips for finding information like the time it was published is by scrolling down and looking around the bottom of the page for any information about authors etc.