The DSM V now includes a section that provides a range of tests and measures. The American Psychological Association, which publishes the DSM V makes those tests and measures freely available online here.
A research center that investigates thoughts, feelings, and associations that exist outside of conscious control. Check out the "For Researchers" section--especially the study materials--for research instruments, stimuli, etc.
A database of documents and articles that may lead you to various tests and measuring instruments. Click "ERIC Descriptors," which will help you browse by category. Some documents can be downloaded for free. For those that can not be immediately accessed, search for them by title in DISCOVER!, and request via Interlibrary Loan