The American Psychological Association is the largest scientific and professional organization for psychology in the USA. Their mission is to "advance the creation, communication and application of psychological knowledge to benefit society and improve people's lives."
The American Psychiatric Association, founded in 1844, is the world’s largest psychiatric organization. It is a medical specialty society representing growing membership of more than 35,000 psychiatrists.
The Association for Psychological Science (previously the American Psychological Society) is a nonprofit organization dedicated to the advancement of scientific psychology and its representation at the national and international level.
Careers in Psychology provides information on how to enter a professional psychology field including licensing requirements, schools that offer psychology programs, and interviews from professionals working in the field.
The Personality Project from Northwestern University provides many articles on topics concerning the study of personality. They also have a link to their SAPA personality test, which is primarily based on the Big 5 personality model, and returns information to you about your personality.
PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.