This is a comprehensive award-winning guide to mental health, psychology and psychiatry online. There are too many resources to list here. This website has a very good self-inventory for depression. Treatment, research and resources for most psychological problems are listed. You can even get an online therapist (but they cost money).
This is a mental health and wellness Q & A Internet service out of Columbia University with an archive of over 1800 straightforward and informative responses to anonymous questions and questions you are probably too embarrassed about to ask anybody else.
This is a one-stop index to multiple mental health websites, forums, and help lines. Also links to self-screening quizzes on Depression, Mania, Adult ADD, Eating Disorders, and Obsessive-Compulsive Disorder, etc.
This site has it all! It defines what mental health is rather than discussing mental illness. It lists mental health books and a glossary of mental health terms. It also gives information on such things as the ability to enjoy life, resilience, balance in life, flexibility, and self-actualization.