Absolutely the best place to start. This resource, part of Diana Hacker's Research and Documentation Online site, should authoritatively answer most questions.
(Note: If the above links take you only to the homepage of the Research and Documentation site, select "Social Sciences / "Documenting Sources" and "APA list of references.")
ZA 4375.H327 2010 (printed copy in Leyburn Reference)
Printed version of the above database is a compact booklet providing an excellent outline of research techniques, including the latest APA Style recommendation. See pages 182-229.
REF BF 76.7.C 66 2010 (printed copies in Leyburn "Permanent Reserve" at Circulation Desk and in Science Reference)
Here is the "short verion" of the full Publication Manual (below), with samples of bibliography entries in "Reference Examples," pp. 209-255.
BF 76.7.P83 2010 (printed copies in Leyburn "Permanent Reserve" at Circulation Desk and in Science Reference)
This is the most exhaustive "official" and up-to-date outline of APA Style. "Reference Examples" for a bibliography are outlined on pages 193-224.
PE 1408.H2778 2011 (printed copies in in Leyburn and in Science Reference)
An excellent general-purpose guide for student writing. APA Style for a bibliography ("APA list of references") is outlined on pages 463-483.