The document defines reference books as books containing organized information like encyclopedias, dictionaries, atlases, and almanacs. It provides examples of common reference books such as encyclopedias which contain articles on many subjects, dictionaries which list words and their meanings/pronunciations, thesauruses which contain synonyms and antonyms, atlases which are collections of maps, and almanacs which contain calendars, astronomical data, and other yearly facts. The document concludes with an activity where groups will use assigned reference books to quickly research a topic and present their findings.