There are two ways to get textbooks via the library, but only one is currently available due to COVID. When we are not in a pandemic, your instructor can put a textbook on course reserves at any of our libraries. Students can then come check out that item, typically for two hours at a time. Many students scan the textbooks, and that is perfectly legal for personal use.
The second method is for the library to own a copy of the textbook. If it is available in our print collections, or if it is available from a partner library, you can check it out for a regular length of time. You can always request that we purchase it: https://library.osu.edu/suggest-additions-to-the-collection. However, that doesn't scale well, so we try and buy multiple-user eBooks when possible. Your instructor would need to contact their librarian to find out if the book is available as a multiple-user eBook at least four weeks before the class will need it. If a textbook is available as a multi-user eBook (and isn't entirely prohibitive in price), I will happily purchase it!