One of the best places to go for the basics of APA is the APA Style and Grammar Guidelines homepage. Below are specific links within that page that are particularly relevant to your assignment.
Recommended sources for help with APA style guidelines:
Many databases and article collections, plus many e-books, will automatically create citations for whichever article or chapter you are viewing.
Look for a “Cite,” “CiteNow,” or “Cite This Item” button on the database record for the specific article or chapter.
(Not all databases have this feature. For example, LexisNexis does not.)
Examples of citation buttons:
EBSCOhost databases ProQuest databases JSTOR
(e.g., Academic Search Premier) (e.g, Newsstand)
There are plenty of citation creators online, but you always need to double-check their accuracy. Never copy and paste without reviewing the citation for accuracy yourself!
APA style requires that a Digital Object Identifier (DOI) be included in your citation, if available. To see if a journal article has been assigned a DOI, you can look it up on CrossRef or Ask a Librarian.
For more information about the DOI system, see http://www.doi.org.