The information in citations appears either in the sentence (in-text) or parenthetically:
In the sentence: According to Kokkinos (2007), employers cause burnout when employees are stressed by too much work.
Parenthetically: Employers cause burnout when employees are stressed by too much work (Kokkinos, 2007).
For quotations of a source, the page or paragraph numbers also is included parenthetically:
Quote: Kokkinos (2007) described burnout as "a negative affective response occurring as result of chronic work stress" (p. 2).
As you can see, the information APA requires for citations helps direct the reader to that particular source in the reference list. Note, then, that is probably a good idea to construct your reference list as you write, allowing you to know what information will appear in all of your citations.
Start with these elements for each citation and you will be headed in the right direction. Check out the other information listed on this site, and if you still are stumped, contact us at firstname.lastname@example.org.