There's something about the smell of a book cracked open for the first time. A freshness, a quality, that gets to a book-lover, or bibliophile every time. Old books have their own smell, dusty and weathered, something that almost makes them seem wise and knowledgeable, but ones bought new or checked out for the first time have a special quality beyond just their newness. There are plenty of ways to go about getting either type of book, depending on what you prefer - the feel, scent and untouched quality of new or the aged, worn feel and scent of old books.
Used and Old Book Options
The most obvious option for getting your hands on a used or old book is going to the library. Most libraries have a good collection of both fiction and nonfiction books, all of which have probably been opened and handled by at least one person before you. Many are even older, giving you a way to get your fix of that old-book smell. If you want a specific title or subject matter and your library doesn't carry it, libraries usually have an inter-library loan program. It involves filling out a request or having a librarian do it for you, then sending that request to the nearest library that does carry the book in question. These programs open up a wide selection of used books that you might not otherwise be able to get your hands on.
Other good options for getting used and old books exist within your community. You might have a used bookstore nearby, which buys used books from local people and then resells them. Usually, these are fairly cheap unless the book is limited edition, signed, or a collector's item, and they have broad selections in both fiction and nonfiction. You might even be able to buy books from your library; they frequently have "Friends of the Library" sales areas in specific parts of the building. Other libraries hold annual sales to clear out their old collections and make room for new books.
In most areas, there are both garage or yard sales and estate sales. In some regions, these take place in specific seasons, since most people don't want to go hunting for good deals when it involves through snow. You might be lucky and hit a sale that has a huge collection of books. Usually, these are well-loved. If you're especially lucky, you'll find that leather-bound copy of the collected Sherlock Holmes stories that you've been looking for over a span of years.
Getting Your Hands on New Books
It's much easier to find a selection of books than it is old. Occasionally, you might find them in some of the same places that have used books; an estate sale might have a collection that was never read before the owner died or needed to reduce their collection of things, or you might be the first to check just-arrived books out of the library.
More obviously, though, you can go to bookstores to find what you need. There are chains like Barnes & Noble that need your business to stay open, but there are also independent booksellers that rely on your business to keep their doors open. Usually, both have excellent selections of books, whether they're new releases or have been around for some time. You should be able to find what you're looking for in a brick-and-mortar store.