Children need two parents if at all possible.  As a child from a one parent family (father died), I'm convinced of the need for a child to be raised by both father and mother.  Your first goal and your utmost responsibility is not only to place children in homes, but to place them in homes that will provide for their over all well being.  Too much evidence is seen to support this.  I've seen too many kids that were friends of my own children live very difficult lives without both parents.  I hope you take your job to place children seriously, and know that your decision to place a child leaves you with a responsibility that goes far beyond than just putting a child in a home.