Pandora and Copyland
When you read the syllabuses of the lectures, you will realize that you need to buy some books. There are two options for buying your compulsory books. First option is Pandora. You can find original lecture books and workbooks at Pandora. It has also notebooks, pencils, pens and another stationery equipments. It categorizes books of lectures and labels them, therefore you can find your compulsory books of lectures easily.

Another option is Copyland. It prepares a photocopy-books which are given by lecturers. Some lecturers ask you to buy a book, but some of them prepare their notes by themselves. If your teacher prepares his/her own notes and give them copyland, you can reach it easily.
The prices of photocopy books are cheaper than original books, but they do not photocopy an original book. You can use Copyland for only, if your lecturer has already prepared notes and gave them to Copyland. If you have hesitation about where to go, you can check your syllabus. In syllabus, lecturers generally mention that where you can buy your books.