Buy the book. Visit a bookstore or newsstand and purchase your own copy to keep for as long as you like. The advantage of this method is that with a little work, you can usually find even the hottest books and read them right away; the downside is that you have to pay money to buy the book.
Since you're paying, be sure to pick up the book and read a few pages of it in the store first, so you can tell if you'll enjoy the author's writing style when you crack it open at home.
Borrow the book. Friends and relatives who recommend a book to you will often have their own copy and be glad to led it to you for as long as it takes you to finish.