Print sources are easy to browse and can provide overviews and references for additional reading.
Below is a link to Credo Reference, which can provide basic and background information.
Most professors do not want you to use Wikipedia as a reference.
However, at the beginning stages of research, it can provide vocabulary, names of important people, and lists of references that you can investigate and evaluate on your own.
Keyword searching--Watch this tutorial from the University of Missouri-St. Louis. If your search term is a phrase, e.g., natural selection, enclose the phrase in quotation marks. "Natural selection" is a more specific search than typing the words separately.
Boolean operators (AND, OR, AND NOT) These words are used to combine your search terms. AND means that every word must be in your search results and will narrow your results. OR is used to connect similar concepts or synonyms and will broaden your results. OR IS MORE. NOT eliminates a word from the search and should be used with care.
Truncation--Use the asterisk * to retrieve all variants of a word. For example, educat* will retrieve education, educating, educator. But be careful! Con* will retrieve convict, contract, constitution and all other words that start that way. You will get many irrelevant items.
Field--A field is the location in the record where your terms are located, e.g., title, subject, author.