APA Exposed (online tutorial)
This online tutorial from the Harvard Graduate School of Education consists of four modules on APA Formatting Basics, Citing Sources, Reference Citations in the Text, and References. Each module includes examples, explanatory slides with audio and textual narrative, and a quiz.
APA Style for Electronic References (online resource from APA - for new edition of manual)
APA Formatting and Style Guide (online resource from the Online Writing Center at Purdue University)
APA Style with examples