American Psychological Association

This organization exists to advance the discovery, application and propegation of knowledge about psychology. Its website contains links to the societies of specific areas in psychology, articles, current psychological news and is one of the primary resources for psychologists. 

National Institute of Mental Health

The NIMH provides access to grants and publication for researchers, large amounts of information about mental health issues, current news articles and much more. 

The Society for the Teaching of Psychology

The STP states that they seek to "promote excellence in the teaching and learning of psychology." They offer resources such as class demonstrations, lists of conferences, e-books, and the Teaching of Psychology journal. Although some areas of the site do require membership, others are accessible to anyone.