When my son was 3 1/2 months old his father almost killed him. He was recently released from prison after serving only 7 years. All the state has done to help us is issue a "no contact order" and transfer his parole to another state. I am now happily married and my son (now 6 yrs) wants the same last name as the rest of us. Since his bio father still has parental rights I cannot change my son's last name without permission. I would like to have him willingly sign over his parental rights but, I do not know what forms I need to have served to his P.O or where to get them?

What State? You ASK him (through whatever means you can contact him) if he will sign. You don't serve him with anything.

Keep in mind that the "no contact" order might be on both sides, yours and his.

You are putting the cart before the horse. Have your husband file for a step parent adoption. You should engage a lawyer for this. The lawyer will prepare the forms as part of the adoption process. If he refuses to sign, there is a good possibility the court will terminate his rights anyway. But they will not do it unless its part of an adoption process. So don't try to get him to sign off his rights first, file for adoption first and make it part of THAT process.