This guide, produced by University of Texas/Arlington, contains an extensive list of tests and measures for the Social Sciences.
Neurotransmitter.net provides an extensive listing of psychiatric rating scales.
This guide, produced by the University of Adelaide, contains an extensive list of rating scales and includes PubMed search queries for scales for specific conditions.
Over its 35-year history, RAND Health has produced many practical surveys and tools for improving quality of care.