Months after landing a job at a Minneapolis-based public-relations firm, Tameka Davis was still looking for guidance on how to excel at the company and eventually move up the ladder. So she signed up for her employer's mentoring program.

The now-26-year-old was taken under the wing of an older co-worker for a year, and the benefits were palpable: She developed a five-year career plan, improved her networking skills and learned how to work better with clients.

"It's just good to be able to talk to someone who has been there and can help you navigate your career," says Ms. Davis.

A mentor can help a young worker answer tough questions about his or her career path and get perspective on the industry. The relationship may even help you eventually land a new job. But you'll need to be careful to pick a mentor whose expertise and attitude are right for you. And it's important to maintain proper etiquette.

Some companies have formal mentoring programs that pair a young employee with a seasoned worker. "In a more formal mentoring program, you set specific objectives," says Deb Cohen, senior vice president for knowledge development at the Society for Human Resource Management. You may be expected to set goals, such as learning about a new part of the company, and formally prepare for each meeting with your mentor.

If you're allowed to pick your mentor, look to someone who can guide your career development and seems committed to the structure of the program.

If your company doesn't have a formal program, find a mentor informally. Consider a co-worker who has a good reputation at the company and is interested in being a mentor, says Hallie Crawford, an Atlanta-based career coach. This could be someone in your department whom you want to emulate; someone outside your department whom you've worked with on a project; someone in a department you hope to move to; or someone who has a professional interest in you.

Ms. Davis works with financial-services firms, but she picked a mentor in the interactive and social-media department, which she is interested in getting more involved with. Plus, being outside her department meant the mentor could give objective advice, Ms. Davis says.

Lillie De Alba, 24, met her mentor when they worked on the same team briefly. When Ms. De Alba, now based in Stamford, Conn., was having a tough time deciding between two positions at the company, the mentor helped her figure out how each one would affect her longer-term career path. "It was hard to see so far in advance," says Ms. De Alba. "She helped me see more of the big picture."

Another option: Find a mentor within your industry but outside your employer. "A mentor outside will help you with a broader perspective on your profession," says Ms. Cohen. But you'll want to be careful not to share any trade secrets. You can find this kind of mentor at alumni groups, trade associations and networking events.

You should approach a would-be mentor in person; stop by the person's office or ask him or her to lunch. Outline why you want to work with the person and what you'll bring to the table as a mentee. Ask how often he or she will be free to meet.

When you start meeting, have questions and discussion topics ready, says Ms. Cohen. To keep the relationship active between meetings, send your mentor interesting articles or kudos on any professional accomplishments. But don't try to meet more often than agreed upon or bombard the mentor with emails.

Though your mentor may become a friend, you want to remain professional and limit sharing details of your personal life. "Realize they are there to help you, but they're not your parents," Ms. Crawford says. "You need to keep that boundary."