I live in the state of California and a friend has offered to "sell" me his sperm, how do I protect my rights and avoid a situation where I risk him wanting parental rights? He is related to my partner, so its not a current fear, but I want to be protected. He has agreed to release his paternal rights, but is there a form that needs to be filled out? I don't want to deposit the sperm with a Dr or sperm bank, are there any other options? I understand listing unknown as the father on a birth certificate is not enough, are there any other safe guards? Any information is greatly appreciated.

Get a Family Law attorney to draw up a contract.

If your not using a anonymous source and your not using a sperm bank then it might be tough to relinquish rights of a person before a child is born. You can check here for more info but all I found was a reference to adoption and a sperm donor with the basics saying you needed paperwork from the agency or a doctor stating such.

Good Luck
California Courts: Self-Help Center