I would be sure to ask her/him some questions. Examples that I sometimes ask:

What method or approach do you use, what does a session typically look like?
How will you help, specifically?
Do you have experience with [particular issues]?
Do you seek supervision regularly?
What do you do in the case of an impasse or other conflict?
What do you do to minimize the power imbalance inherent in therapy?
Have you ever imposed termination on a client?