adopting from sister

My sister has two children and wants to give the youngest one up. I would like to adopt him. The only problem is that i am a single young woman of 21. I graduate from college in a year and am planning to move across the country. My sister is willing to give the child up and I am already looking for jobs. Will there be a problem with me adopting this child because of my age and the fact that I am just starting off? Also, my sister is a single parent. The father of the boy is in jail and isn't allowed contact with any children. What are the birth father's rights since he hasn't been in the child's life since he was a baby?