California Divorce- If serving my husband by mail, do I send the whole divorce packet?

I am in California and I am trying to get my husband served with divorce papers. I have a fee waiver, and everything is filled out. What I do not understand is what part of all the paperwork I mail to him to serve him. I cannot have anyone serve him in person because he is incarcerated. It states in the paperwork I can serve him by mail with certified proof, but what papers do I send? Just the one paper he signs?