Booking agents are an essential connection between a movie's distributor and the cinemas. Not only do they negotiate the contracts with the distributors and producers, but they also organize the fabrication and transport of the film prints and the supply of marketing material, such as posters. Major cinema chains have a booking agent employed in-house, but smaller independent theaters turn to freelance agents that work either for a percentage of the ticket sales or on a retainer. A good booking agent's incentive should always be to keep as much of the ticket sales at the cinema box office and forward as little as possible to the Hollywood studios.
Pick up the phone and call around to other cinemas in the area. Talk to the managers and explain your problem. The movie business is vain and being asked for professional advice is flattering, so most cinema owners or managers will be glad to help.
Visit local film festivals, get an industry accreditation as a theater owner/manager and mix with the professional crowd. Film festivals and markets are not only audience magnets, but usually represent a meeting point for the film industry, including booking agents. Ask the press or marketing officer to introduce you as they settle the accreditations and will most likely know who is who.
Phone a distributor of a film that you would like to book for your cinema. Ask for the booking department and require the phone numbers of booking agents in your region. Film bookers have to be in continuous contact with distributors who most likely have an entire database for booking agents.
Consider employing your own part-time film booker. You have to pay for the job, anyway, and getting a self-driven person with some film business knowledge might even be cheaper in the long run.
Book a ticket to the American Film Market (AFM) in Los Angeles or to the Cannes Film Festival in France. It will be expensive, but both markets assemble the entire film trade for a couple of weeks, and every film booker in the country will attend.
When hiring a booking agent keep in mind that this is business, and a middle-aged, slightly-overweight accountant probably has a better eye for a bargain than the hundreds of hip film buffs who will apply for the job.