What are the first steps to getting custody and primary placement of my son?

A filing will need to be made in the jurisdiction where the child resides. Then if you believe the parents will not agree on custody and placement a GAL and court appointed psycologist will be appointed. These two will investigate the environments and complaints between the parties, and decide the best interest of the child, and then make recomendations to the court. It is a rather long and expensive process.

I hope this helps.