Although you would like to do this on your own, adoptions are very complex in terms of the process. Also, since you do not know the whereabouts of your daughter's biological father, he will likely be served by publication and an ad litem attorney will likely be appointed to represent his interests. You should consult with a family lawyer before attempting to do this on your own. Many give free initial consultations.
The information provided is not advice but a legal perspective and you should schedule a consultation with the lawyer of your choice.
I agree. (Although my answer would have been to go to law school...)
Adoptions require terminating the parental rights of the biological father and Mother. Not easy to do right - even when they agree.
Do yourself a favo - hire a lawyer.
The procedure here varies from jurisdiction to jurisdiction. I understand you are hesitant to hire a lawyer if you can do it yourself but it is really in your best interest to have a Family Law attorney navigate the waters of the stepparent adoption for you. There are likely going to be collateral issues that arise that a lawyer will be able to help you with as well.