I am a single mom of two boys. Their father is not in their lives in any way and has not signed their birth certificate or anything like that, I don't even know how to find him. I am getting married soon and would love for my children to have the same last name as me. How do I go about doing this?

Have your new husband adopt them.

Chuck

Usually by the new husband adopting them. Until that happens their birth father still has parental rights he might decide to exercise... unless those were taken away by the courts.