The AND tells the computer to search for both terms (librarians AND well-being, for example). The OR tells the computer to look for either of the terms (for example, well-being OR health).
Then you can limit your search for:
O*NET Online provides basic profiles for numerous occupations. The U.S. Bureau of Labor Statistics has handy resources, including the Occupational Outlook Handbook. If your occupation has a professional association (for ex.the American Nurses Association), you might find useful information at the association's website.