You can adopt through domestic private adoption (newborn), or through foster care. You will want to consider if you are adopting as a single or with your fiance. We adopted a biracial girl in Atlanta GA (we were living in CA, but the mom was in GA).
For domestic private adoption...You need to find an adoption agency that you like and get started with them. When you get further into the adoption process you are asked about what kind of adoption situations you are open too... health, ethnicity, level of contact with the parents, father unknown... Then as they contact pregnant women through outreach they try to match you based on your criteria as well as that of the mom (is she open to a single woman...)
For a foster care adoption... contact the agency in your county that deals with foster care. You'll go through a homestudy, classes etc. With fost-adopt many of the children are older, so the wait is usually longer if you want to adopt a young child or infant.. but talk to your local agency and see what their experience is These kids really need permanent homes.