Mentors can do several things to help you develop your skills and advance in your career. When choosing a mentor, consider what you want to learn from that individual. What skills do they have, and what experiences and perspectives do they offer that can help you? How much time do you want to invest, and how much time do you expect from a mentor?
A mentor can encourage you to try new things, especially things you may not have seen yourself doing. He or she can guide you and critique your work in a constructive manner without being your supervisor. Often, a mentor can introduce you to new people and opportunities.
Be upfront and honest as you discuss the type of working relationship you will have. Go with a plan, be open to changing the plan, and be prepared to know when you need to end the relationship.