In terms of actual supplies, some pens, some pencils and scratch paper is usually enough. Don't worry if you don't have a computer because they are available in the computer labs in the UGL, some of the dorms, and various departments around campus. Printers are also available. For example, a fan might be useful if you like to sleep in a very cold room. With regards to buying books for classes, it's best to get them as soon as possible.
Used copies are cheaper than new ones, but there's limited amounts and they go fast.
Additionally, you can buy used books directly from other students using the official online service at TexBooks . When buying, you might also want to ask fellow Dean's Scholars if they had those classes and might have kept their books. In fact, other Dean's Scholars are going to be good sources of information in general. They can give information about things to do and classes to take. There is also a reference book about professors and classes available in the Dean's Scholars room that you might want to peruse before final registration, as well as the online course instructor surveys .