Here are two links to services that will automatically build your citation in APA style:
Citation Builder (NC State)
Citation Machine - APA Format
Citation Machine - APA In-text Format
Zotero is a free research tool that allows you to easily organize references, create in-text citations and bibliographies, and much, much more!
RefWorks is web-based software that helps researchers gather, manage, store, and generate citations and bibliographies.