You can look up 'Research Instruments' in Nursing Reference Center--go to Advanced Search and uncheck everything except 'Research Instruments'. You will get a summary of the instrument (type, what it measures, population, etc.), the source (book, article, publisher) and related articles, mostly studies which used the instrument. Use the Journal Title Search (on the Library Home Page) to see if we have the articles, and SouthernSearch to see if we have books, and Interlibrary Loan for anything that we don't have access to. If only a publisher is given, you will need to contact them--these tests are licensed and not available in libraries.
This search box will search the other two test/instrument databases, Health & Psychosocial Instructions (HaPI) and Mental Measurements. Look up the subject that you want the questionnaire to be about, like 'smoking', 'lifestyle', or 'diet'. The databases will give you summaries of the test and the source--which may be a journal article, a book, or a publisher from whom you will need to buy the instrument. Again, check journal finder and CONSULS, or Interlibrary loan, for articles and books, and contact the publisher for other materials.