In these days of e-readers, not as many people buy paper-based books. However, some books are just better to have in a non-electronic format.
For new books, you can visit your local bookstore. As well, you can use a website like Amazon (www.amazon.com) or Barnes & Noble (www.barnesandnoble.com).
However, if you want to get a copy of a used or out-of-print book, the above options may not work. In that case, I would suggest going to AddALL (www.addall.com) which specializes in locating such books. They can search the inventories of over 40 book stores and 20,000 book dealers.
Using AddALL, you can also find very specific versions of the books you seek. You can choose hard cover, first edition or signed books. You can also search for books in a specific condition or for those that have the original dust jacket.
