how do i go about suing a hospital for malpractice?

my daughter was born with a terminal illness and her father and i feel that the hospital neglected to give her certain care because of the diagnosis she receive. she is now a year old and we are just now finding out that there were evaluations and procedures that should have been done with in the first few months of her life that we were not told about or given a choice as to whether we wanted to pursue them or not. now it is too late to go that route and our only option is to go through with a procedure that has a more than 50% chance of not working and could harm her further. so we are looking into suing the hospital but we need to know where and how we should start