I have a 3 year old. My husband is not his father. However his father has agreed to sign over his rights so that my husband can adopt him. Is there any where that I can get the papers or do I actually have to have a lawyer?

There are many online sourses ( you can do a goggle search)
This is one I found in 20 seconds

Online Adoption Forms and Information: Step Parent Adoption Forms:Grand Parent Adoption Forms: Step-Parent Adoption Laws

I would never do it myself without an attorney ** and I went to law school, since adoption is first complicated and one thing done wrong or not filed right could make it invalid down the road.

I would use a lawyer if I was doing it, but forms are available online by state.