Find a club where you would like to offer your DJ services. It should be a club that typically features the kind of music that is best represented by your music collection. It's not a good idea to approach a club that plays house music if you prefer to DJ with rock music.
Visit the club when it's open. You want to get an idea of the type of crowd that goes to the club and how they respond to the music. This will also give you insight into the type of atmosphere that the club has when it's open and operating. You need to gain this insight before you pitch your DJ services.
Create a sample party CD to show how you would play if you were in the club. This sample set should be at least 15 minutes long, but not longer than 45 minutes. If it's shorter than 15 minutes, you won't be able to showcase your ability to DJ a party that could last from 10 p.m. to 2 a.m. If it's longer than 45 minutes, the club manager or owner may not listen all the way through. Thirty minutes is a good average for a sample set.
Make contact with the club. Stop by one night when the club is open, but do it early in the night. If the club opens at 9 p.m., get there between 9 p.m. and 9:30 p.m. Typically the crowd will be light and you might be able to speak with a manager. Find out who hires the DJ and get their contact information.
Make an appointment to audition or drop of your CD. Sometimes DJs are required to do an audition to show how you would rock a party. Other times you will just be asked to give them a CD. Either way, you should be prepared for both.
Stay in touch. If you have to go through a promoter, support that promoter's events, whether they are at the club where you want to work or not. When you attend the parties, stop the promoter to greet him and follow up the next day. If you need to work with a club employee, support the club. Attend different club events, making sure you follow up with the employee the next day.