The Purdue OWL site provides guidance for basic citation and paper formatting (APA, MLA, Chicago, AMA, IEEE).
Citation tools (sometimes called citation managers or reference managers) are programs that help you organize and cite your sources. You can:
Purdue OWL has created a useful online guide of the APA citation style. This online guide includes descriptions and examples.
The following video was produced for Hayden Memorial Library; it contains useful information about APA citation style:
14b - APA from Joshua Vossler on Vimeo.