There are numerous available websites for educational purposes. Authorative resources include:
National Institutes of Mental Health: the best available mental health resource.
National Institute on Alcohol Abuse and Alcoholism: the best available alcohol resource.
National Institute on Drug Abuse: the best available substance abuse resource.
National Library of Medicine: offers access to the world of medical research literature.
Cochrane Reviews: has extensive well-done reviews of studies of diagnosis and treatment in medicine, including psychiatry.
PubMed: to search the vast medical literature on any topic.
PsyBlog: interesting psychological articles about daily life.
NAPS: New Articles and Publications on Sleep: clearinghouse for information on sleep and sleep disorders, sent free weekly to you.
And, I have an increasing number of articles, reviews, and slide show presentations at my education website: Neuropsychiatry Unlimited.