Reference works are a great place to start your research. They are not intended to be read from beginning to end, but rather to provide a quick overview about a subject or person. You can find useful background information, as well as references for further reading.
Just as you might have used Wikipedia, these encyclopedias and publications can help you understand an unfamiliar topic before delving into deeper research. They are preferable to using crowd-sourced encyclopedias, because they are definitive and authoritative - ensuring all content is high-quality, reliable and written by experts.
Note that students generally should not be citing encyclopedia articles, as they do not provide analysis or new perspectives, so check with your lecturer if you plan to do so.