I think the first question is to ask yourself why you are seeking a spiritual director and what you want from one. That will help you figure out who might serve in that capacity.
You should be aware that the relationship between a director and directee is not friendship and a friend or relative would not be a good director. In some ways it’s like the relationship between a doctor and patient. You may love your doctor, trust him, rely on him, but when you see him it’s not exactly mutual. He’s asking about your health, you’re not inquiring about his.
A director may be in almost any walk of life: priest, deacon, religious, layperson. Some people have strong feelings that a director should fall into a certain category. For example, if your director is a priest he can also be your confessor, and since there are links between the two aspects of your spiritual life it can be very helpful. Some people want a director of the same sex or of the opposite sex. Some people want someone who shares certain aspects of their lives such as being married or having children. All of these would influence who might serve as your director.
Finding a director may be easy or difficult. Start by praying and asking the Holy Spirit (the true spiritual director) to help you. You might start with your pastor and ask for advice. Priests may or may not be available – some are too busy, some are not especially interested, some are not qualified. But they may know of someone who is available.
You might also check with local monasteries, convents, or retreat houses. Again, they may have someone available or may be able to refer you to someone. Some dioceses maintain lists of spiritual directors.
Don’t be afraid to drive some distance if you find someone good. My director started out quite close to me then moved to a parish an hour and a half away. I consider the drive to be a good investment and, especially after our meetings, it gives me time to think.