For certain research questions you may want to find certain sources of information:
Reference Sources: include encyclopedias, specialized dictionaries, handbooks (Database: Gale Virtual Reference Library)
Articles in Newspapers and/or Magazines: these are articles that are poular in nature. Direct, clear, easy to understand sources written for the general public (Databases: Readers Guide Full Text or Custom Newspapers).
Peer-Reviewed (Scholarly, Refereed) Articles from Journals: in other situations you may need very detailed, expert analysis of a subject. Articles of this sort are typically scholarly in nature. (Database: Academic Search Complete)