You can look on your state's website to find the forms or talk to an attorney. Since he does not know the child you should be reasonable and purpose a phased plan that includes visits with the child in public places initially and eventually moves to the standard every other weekend visits.
Did she file for child support or was it required due to her being on welfare? Just curious. Does the child have a current father figure? Will this be very confusing for her. It is complicated and you will probobly end up with a guardian ad litem involved who will make recommendations as to what is in the child's best interest. Most likely it will involve counseling all the way around. I would budget $6,000-$10,000 in order to attempt to establish this relationship and regular visitations.