We believe we have reached an agreement as to care of the children and wish to formalise the agreement. What do we do now?

You will need to have Consent Orders prepared. These are a written agreement which states all arrangements related to the care of the children including who the children live with, visitation, shared living arrangements, religious instructions, health care and so on. Consent Orders are sealed by the Court making them binding on the parties which helps greatly if a dispute later arises.