Proper (that is, APA style) form is essential for writing reports in psychology.  Many academic disciplines have adopted the APA conventions.   Other disciplines also often employ the conventions of the Modern Language Association (MLA) or the Chicago Style Book.  Some disciplines further modify those conventions. 

Obviously, the APA sites will be the final authority for writing psychology papers.  The other sites listed may provide clearer examples.  Try several when you are in doubt.  Regardless of which one you use, be aware of the increasingly common standard of showing the date you visited the site.  Doing so helps your reader to "guess" why they cannot connect to frequently moving sites. 

You might also want to visit some of the Evaluation Sites, to find out what practices you should avoid in order to prevent the pros from thinking you are an unreliable source of information.  It is not all that difficult. 
 

APA Writing Style

APA Style Manual
General Instructions for a Psychology Research Paper
Introduction: poster presentations
Preparing a Laboratory Report in APA Format
Web Extension to American Psychological Association Style (WEAPAS)

Modern Language Association Documentation  (not responding)
Beyond the MLA Handbook (Harnack/Kleppinger)  (not responding)
Walker/ACW Style Sheet

Library Research / Writing Guides and Tutorials
Citing online sources  (not responding)

Citation Guides for Electronic Documents — links to many sites for many disciplines. 

Criteria.html  (not responding)
Evaluating Web Resources
Web Evaluation: Criteria