Phone books provide lots of information. Though much of that information is now also online, there's something convenient about being able to page through a printed phone book. A phone book for a city other than the one you live in can be a valuable resource. You can get information about businesses that are competitors of yours, find names of businesses that might provide services you need, and look up the names of residents that live there. You can probably get one for free with very little effort.
Call your phone company. If you are looking for a directory in a nearby city, chances are the phone company can order a directory for you. If they can't, they can probably tell you how to get one.
Determine which directory publishers publish directories for the city you are interested in. There may be more than one and different locations have different directory publishers. Visit YellowPagesOptOut.com. This is a site meant to help people opt out of receiving a phone book at their home. You can use this site to find out which publishers distribute directories in the city in question. Enter the zip code of the city in the search field.
Contact the directory company. Many of them have a form on their website where you can order phone directories. Some of these are listed in the resources section below. If you can't find a form or don't want to use it, use the contact section to find out how to call them and request a directory.