Subject encyclopedias provide great overviews and can often get you off and running with a topic. They also provide citations and references to other resources and some include short biographies.
The Diagnostic and Statistical Manual of Mental Disorders has been a core resource for psychology and psychiatry for the last 50 years. This new 5th edition is the first to be offered online.
Ulrich's is the authoritative source for information about specific journal titles. Find publisher information, reviews, pricing data, and historical information about titles.