Reference materials like dictionaries and encyclopedias provide important background information for understanding your topics. If you can't clearly define the theories you are researching, you won't be able to understand the scholarly research.
Use these materials before you start reading articles, and then revisit them when concepts are unclear.
Need a definition for a sociological concept and don't know which one to trust? Use these dictionaries with confidence.
Look beyond Wikipedia with these excellent scholarly resources that will help you more fully understand key sociological concepts and theories.