When Richard Shirley graduated from business school three years ago, he worked with a career coach to help him focus his job search. His school provided the outside coaching services free of charge, but he was still disappointed with the advice he got.

His coach picked apart his resume, but he didn't feel confident in the changes she suggested. She also handed him a questionnaire about his background and goals and a hand-drawn diagram about how to allocate his time during a job search.

"I couldn't help but think that that's something I could easily do on my own," says Mr. Shirley, a 37-year-old Waldwick, N.J., resident. "She kept hitting me up for other services that I might be interested in the future," he adds. Three years later, he still gets e-mails from the coach promoting her services.

In June, Mr. Shirley was laid off by an international media company and says he would consider working with a coach again. But today, he would look for one with knowledge of his industry. "I would definitely do my homework and research what types of services are available," he says.

The career-coaching industry has been growing steadily for years now and attracting people with a wide range of backgrounds. By some estimates, there are more than 15,000 coaches in the U.S. Extensive training has become more widespread, but some in the industry complain that some certifications are easy to get and difficult for clients to evaluate.

Some people have also charged that many coaches have entered the lucrative field primarily for financial gain, rather than out of a passion for helping others work through issues and develop their careers. Some coaches can be charismatic at first blush but not be very good at helping you find solutions and motivating you.

Choosing the wrong coach "is a loss of money or time, but more than that it's discouraging," says Josh Ehrlich, dean of a master's program in executive coaching that is jointly sponsored by BeamPines Inc., a New York human-resources consulting company, and Middlesex University in London. The first class will graduate from the BeamPines/Middlesex University program next spring.

So how do you pick the right coach to help you with your career?

According to Dr. Ehrlich, first you need to understand what kind of coaches are out there, and he points to three main types.

First are executive coaches, who are often hired by companies to work with employees. They are called in to fix a manager's behavior, help a high-potential employee make it to the next level or help improve an employee's flagging performance.

Second are career coaches, who often help people outside the corporate setting who are between jobs to land a new position, or else work on issues that arise in the workplace. They also commonly help people figure out what they are passionate about and develop a map for the long journey of their careers.

Third are life coaches. They have become more popular in the past few years and "tend to say they do it all," including advising clients about personal relationships and emotional issues, says Dr. Ehrlich.

Other coaches may call themselves by a variety of names which sometimes indicate their specialty: "interview coach," "relationship coach," "productivity coach," "workplace coach," "resume coach."

Once you've determined the type of coach you want to work with, you can begin to narrow the field.

Network with colleagues and friends to see if they can recommend a coach. You can also visit the Web site for the International Coach Federation, a Washington nonprofit professional association for coaches, at www.coachfederation.org. The group credentials individual coaches and accredits coach-training programs.

In general, it's a good idea to look for a coach with extensive training, even though some gifted advisers may have limited formal training as a coach. Be sure to investigate certification requirements. While some certifications may be easy to come by, others are rigorous. For example, the ICF's master certified coaching designation requires 2,500 hours of client coaching, among other requirements.

Since coaching requires an open exchange and personality comes into play, you'll need to go with your gut instincts about a coach. Tony Siciliano, a senior sales executive in Framingham, Mass., met a career coach last year at a networking event, and "I could tell right away that she could help me," he says. The first time Mr. Siciliano, 48, worked with the coach, she helped him become less negative toward a previous employer during job interviews, and he got the next position he applied for. "You can't argue with results," he says.