Proper (that is, APA style) form is essential for writing reports in psychology.  While many other disciplines (including, but not limited to: Sociology, Business, Economics, Nursing, Social Work, and Criminology) use APA writing style and referencing formats, some other disciplines employ the conventions of the Modern Language Association (MLA) or the Chicago Style Book.  Some disciplines further modify those conventions. 

Obviously, the current Publication Manual of the American Psychological Association or other APA sites should always be considered the final authority for writing psychology papers and papers in the disciplines shown above.  An online guide to referencing some forms of electronic media is maintained at APAStyle.org.   Unfortunately, there are not many examples and there is no detailed discussion or example of the most common sort of Web pages that might be used in a paper for a psychology course — pages such as this one. 

The other sites listed below may provide clearer examples.  Try several when you are in doubt.  Psychology students in some classes are not likely to go too far wrong using the forms of citation shown in the WEAPAS document because APA appears to have moved in those directions.  Some professors even prefer the WEAPAS format because of some unresolved issues about the APA format.  If in doubt, ask your professor. 

Regardless of which format you use, be aware of the need for showing the date you visited the site.  Doing so helps your readers to "guess" why they cannot connect to frequently moving sites or do not see some information to which you refer. 

You might also want to visit some of the Evaluation Sites, shown below, 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. 

The two most basic kinds of references that you are likely to need to use are those for books and those for web sites.  Both share several common features, but they do differ. 

For web sites or pages, you will need to show the name(s) of the author(s) or the organization that produced the material, or the name of the person responsible for maintaining the site.  This is followed by the date the page was placed on the web, or the date it was last updated.  The third element of the reference is the name of the site, or the title of the specific page you are citing.  This is seen in the band at the very top of the browser screen (probably a blue band unless you have changed the default setting of your browser).  The next element to show is a "retrieval statement" that includes the date you last visited the site or page.  Finally, the URL is shown.  Note that the URL in a reference is not followed by a period.

For example, the proper APA-style form of citation for this page should be:
Nichols, J. W. (2003, February 5). Tips on Writing Research Reports. Retrieved February 6, 2003, from http://www.tulsa.oklahoma.net/~jnichols/Writing.html

The proper form of citation for showing the online version of the textbook I currently use in my Introduction to  Psychology (PSY 1113) courses as a reference for an assignment would be: 
Franzoi, Stephen L.  (2002).  Psychology: A Journey of Discovery.  Retrieved December 28, 2002, from http://www.AtomicDog.com

(TIP:  In email messages or on Web pages, do not end the URL with a period unless you know how to do it properly.  Punctuation improperly placed at the end of the URL will prevent it from becoming an active link to the site you to which you are referring the reader.  In fact, an error message will be received when your reader clicks on the link.)

For books, such as your textbook, you first show the name(s) of the author(s), followed by the date of publication.  Unlike some Web pages, books are not updated frequently, so only the year of publication is necessary.  The third element of the reference is the full title of the book.  The title should be underlined when typed or written by hand (to indicate that it is to be shown in italics), and should be italicized when done on a modern word processor.  The title is followed by the city and state where the book is published and the name of the publishing company, separated by a colon. 

For example, the proper form for showing the textbook I previously used in my Developmental Psychology (PSY 2023) courses as a reference for an assignment would be: 
Berger, K. S.  (2001)  The Developing Person Through the Life Span (5th ed.).  New York, NY: Worth Publishers.

The proper form for showing the print version of the textbook I currently use in my Introduction to  Psychology (PSY 1113) courses as a reference for an assignment would be: 
Franzoi, Stephen L.  (2002).  Psychology: A Journey of Discovery.  Cincinnati, OH:  Atomic Dog Publishing.
 
 

APA Writing Style

Electronic Reference Formats — APA's own, official standards excerpted from the new 5th edition of the Publication Manual.  One problem is that APA does not provide examples of how to cite regular web pages such as this one.  Until they do, you might also try using one of the reference formats shown above or at the bottom of this page.

APA Style Manual  — Mark Plonsky's updated Psychology With Style: A Hypertext Writing Guide (revised 1/17/2000).
General Instructions for a Psychology Research Paper  — Jan Kennedy's guide to writing a traditional paper (on paper) that would be submitted in class.  Old, but informative.
Introduction: poster presentations  —  Jeff Radel's instructive guide to preparing a poster to present at a poster presentation session. 
Preparing a Laboratory Report in APA Format  — Jan Kennedy's guide to writing a traditional lab report (on paper) that would be submitted in class or for publication in a journal.  Old, since it is based on the 4th edition of the APA Publication Manual, but instructive.
Web Extension to American Psychological Association Style (WEAPAS)  — More examples than APA's site provides and largely as APA decided.  The minor differences will probably not get you into trouble with anyone other than APA journal editors, but it is always a good idea to check with your professor when in doubt.
 

Modern Language Association Documentation
Beyond the MLA Handbook (Harnack/Kleppinger)
Walker/ACW Style Sheet

Library Research / Writing Guides and Tutorials
Citing online sources

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

Criteria.html
Evaluating Web Resources
Web Evaluation: Criteria

Nichols, J. W. (2003, January 4). Tips on Writing Research Reports.  Retrieved January 29, 2003,  from http://www.tulsa.oklahoma.net/~jnichols/Writing.html