My stepsons brother is 14 and wants to come live with my husband and I. We want to adopt him and don't know how or what to do. His dad is in jail and his mother is not around. They are both horrible parents and he just really needs parents. What do I do?

Who has custody of him now? Isn't your spouse his parent? The first thing to do is petition the court for guardianship so you can get him into a safe environment (assuming he's not in one now). A lot depends on where he is now and where you live (ANY question on law (and this has been moved from the Adoption forum since it is a legal issue) need to include your general locale as laws vary by area).

The other thing you need to do is consult a Family Law attorney in your area since you will need one to prepare the adoption petition.

... Isn't your spouse his parent? ...

If he isn't the son of the OP's husband, perhaps he is the former step-son of the husband (from husband's previous relationship with the mother of the two boys?). I agree, this is confusing.

In any case, yes. OP would have to file a petition with the court, and to do that should get an attorney. And at some point you are going to need the formal consent of the child's legal parents.