For those seeking quality physics books, online bookstores are recommended as they offer a wide selection of both new and used textbooks. Notable options include Barnes & Noble, Borders, Amazon, and Alibris, with Amazon Marketplace often providing competitive prices. College bookstores are also a viable option, as they sell textbooks to anyone, not just students. It's suggested to consider slightly older editions of textbooks, as they can be significantly cheaper while still providing relevant content. Caution is advised when purchasing online to ensure the correct edition is received, and many platforms offer money-back guarantees for peace of mind. Additional search sites like AbeBooks, CheapBooks, and eBay can yield good deals, especially during certain times of the year.