Section 5334 of Act 112 deals with the appointment and duties of a guardian ad litem. Section 5335 deals with the appointment and duties of a child counsel.
In a custody dispute, a guardian ad litem ("GAL") represents the "best interests" of the child, while a child counsel represents the child's "legal interests". In other words, the GAL is appointed to help the court understand what is best for the child, while counsel would represent the child's wishes in court. The GAL will also convey the child's wishes to the court, but can contradict those wishes with her own assessment of the child's best interests.
In practice, a GAL is far more common. After all, a 10 year old child is not really in a position to rationally retain counsel to represent his legal position. The GAL will often issue a report on the child's best interests. Neither the GAL nor the child child counsel will generally testify himself. In either case, Act 112 permits the court to apportion costs for the GAL or counsel at it sees fit.
Act 112 does not represent a large change to prior custody practice, but it does create a basic framework for operating with a GAL or child counsel. Act 112 does say that a GAL must be appointed if "substantial" allegations of abuse are made and the GAL is needed to provide relevant information to the court.