Finding a therapist is like any other consumer issue.  It pays to do your homework.  All states have professionals licensed to do marital therapy.  A good therapist will have special training in marriage therapy and of course experience.  In my home state of Georgia those professionals qualified to practice marital therapy are marriage and family therapists, ministers, professional counselors, clinical social workers, clinical psychologists and psychiatrists. 

Referrals

Direct referrals are your best source for marriage therapy.  A friend who has seen a marriage therapist is a good beginning.  Medical doctors, ministers and other mental health professionals are all good sources, just make sure they have direct knowledge of the therapist.

If you have no direct referral, the American Association of Marriage and Family Therapists has a website, aamft.org that is a great resource for further information and will help you find a therapist. 

Screening

Do not be shy about asking questions of the therapist before your first visit.   Any good therapist will be happy to tell you about their qualifications and experience.  The therapist should be able to tell you about the first meeting and what will be covered.  Cost, approximate length of treatment and available times for meetings should be discussed.  Look for an ease and openness about their therapy.

Not all therapists fit all people seeking marriage therapy.  If you or your partner feel the therapist is not right for you, find another.  Do not give up on therapy because of a bad experience.  If you are simply unsure of your therapist, try another session, but be open about your concerns.  A good therapist will try to address your concerns.  Also, remember that marital therapy is very difficult and that your problems with a therapist may be within yourself or your partner.