At the beginning of the research process, it's very useful to get an overview of your topic. Encyclopedias, dictionaries and other reference sources are a great way to get started and to find background information on your topic from various perspectives.
BEAM note: Although encyclopedias are often used as a background, depending on your research question they may serve a different purpose in your writing.
If you are researching a contemporary topic related to a social issue (such as human trafficking, LGBT or Transgender rights, mass incarceration, etc.), try the CQ Researcher database. It covers the most current and controversial issues of the day complete with summaries, insight into all sides of the issues, bibliographies, and more.