It is highly recommended that you purchase the texts for each subject in which you're enrolled. You are often asked to read chapters from these texts on a weekly basis. Sometimes, textbooks are available to borrow from the library or for viewing online as ebooks. All textbooks are kept in the library's reserve collection for reading in the library only.
Your book list is available on this page: Textbooks and course materials.
Look at these links for more information:
Purchasing and borrowing textbooks: Textbooks page.
How to borrow books: Borrow page.
Finding eTextbooks: eTextbooks list.