Many databases allow you to limit your results to Scholalry or Peer-Reviewed Articles. This option is usually found on either side of your results list and/or in the advanced search screen. Use this to limit your results to college level research written by and approved by experts in the field.
To help narrow your search, search for subjects related to your topic instead of the default keyword search. You can usually see the subjects an article covers by clicking on the title of that article from the results list. Use those subject terms to find more articles on that topic.
Use the databases limits options to narrow your search. Date, type of document, and language are just some of the options you can usually limit your search by. Limits options can usually be found on the advanced search screen and/or to either side of your results list.
Use truncation to search for multiple forms of a word. Truncation symbols may vary but it is usually the * or ? symbol. Example: comput* will search for "computer," "computers," "computing," "computation," etc.
A wildcard is a character you can insert in the place of another character. It will search for different spellings and word variations. The wildcard symbol may vary but it is usually the ? or ! symbol. Example: "wom?n" will search for both "woman" and "women."