First, go to orbit https://rollestoncollege.softlinkhosting.co.nz/oliver/junior.do
Click "search", then "subject" and type in the topic you are wanting to learn about.
Make sure to click "fact", so you know you will only get non-fiction books.
Take note of the classification number and the first three letters of the author's name so you can find it in the non-fiction section of the library.
The Dewey Decimal System
The 10 Main Classes
000 – 099: Computer science, information, and general works (encyclopedias, journalism)
100 – 199: Philosophy and psychology (ethics, logic, human behavior)
200 – 299: Religion (world religions, mythology, the Bible)
300 – 399: Social sciences (politics, law, economics, education, customs)
400 – 499: Language (linguistics, dictionaries, grammar for specific languages)
500 – 599: Natural sciences and mathematics (physics, chemistry, biology, earth sciences)
600 – 699: Technology and applied sciences (medicine, engineering, agriculture, home economics)
700 – 799: Arts and recreation (architecture, music, painting, sports, crafts)
800 – 899: Literature (poetry, plays, essays, and literary critiques)
900 – 999: History, geography, and biography (world history, travel guides, collective biographies)