It can be helpful to read an encyclopedia article on your topic to get some background, concepts, keywords, etc. Many encyclopedias also have bibliographies at the end of articles which can start you off on your research. Not every topic may be represented in an encyclopedia, but if they are, it can be a good starting point.
• Handbook of Personality
O. P. John, R. W. Robins, & L. A. Pervin (eds.), Handbook of personality (3rd ed). New York: Guilford Press
• Cambridge Handbook of Personality
P. Corr & G. Matthews (eds.), Cambridge handbook of personality. Cambridge, UK: Cambridge University Press.