An initial call to a therapist's office should be returned within twenty-four hours during business days or the following business day if placed during a weekend. Ask up-front what the therapist's policies are regarding phone calls. Trust your intuition. If you feel uncomfortable with a therapist after a couple sessions don't keep hoping it will change. One of the reasons psychotherapy is successful is the relationship between the therapist and client, if this relationship is not good, therapy has little chance of working.
Therapy can be a life-changing experience or an exercise in frustration.
As with any professional service, care must be taken in choosing the professional you trust. Talk to friends about things they found valuable in their therapists. Spend time reading about the kind of therapy you would like to receive. Be an educated consumer.