Locate a suitable venue for the performance. If you're a club owner, then you're already set. If you're not affiliated with a venue, you'll need to find one that can handle a country concert, and have the capacity for the potential number of people attending.
Plan a date well in advance. While local or unknown country singers might be able to play a show that's happening two weeks from now, national and established country singers generally need several months notice to fit a show into their busy schedules.
Formulate an offer regarding how much you can pay the country singer. Consider your budget and whether you'll be selling tickets or not. Be realistic. Randy Travis is likely not going to play for $300, while a singer from the local college might.
Contact the singer or his booking agent. Most country singers have a website with a contact page where they list how to get in touch with them or their booking agents. If you're having trouble finding this information, search for the country singer's name and representation.
Share your offer and the date you'd like to book the singer. Explain any other information, such as how long you'd like her to play, the nature of the event (concert, charity event, birthday party), expected attendance and what the venue is like. Ask about additional requirements the singer demands, such as sound equipment, a rider or travel expenses.
Agree to sign any contracts the booking agent or singer might send. The singer or agent might also require an advance payment. If that's part of the deal, send the correct amount on time. Turning in payment and contracts on time is important as it keeps the singer happy and less likely to back out on the concert.