Reference sources can be a useful place to start exploring a topic. These sources include dictionaries, which briefly define a term, and encyclopedias, which provide a summary of the work that has been done on a topic.
Credo Reference
Includes 440 encyclopedias and dictionaries. To get to the sociology resources, click on social sciences in the subject listing, then use the menu on the left to further refine to sociology to browse sources.
Oxford Reference
After doing a search, use the filters on the left side to narrow your results to social sciences, then to sociology specifically.