If you're considering adoption, I have looked into adoption a lot, so I can share what I know. (For awhile I was uncertain whether I wanted to TTC at all or just adopt, and I eventually settled on wanting to TTC first and adopt a later child.)
There's basically three types of adoption - private adoption, foster-to-adopt and international adoption.
Private adoption is the best way to get a newborn with no special needs. You put your information in a listing and a prospective birth mother picks you to raise her child, usually while she's pregnant. You might even get to be at the birth, depending on how things work out. This route is usually open adoption, meaning that the birth mother knows you and vice versa, you send updates on the child and maybe they meet up sometimes. There's a grace period after you gain custody where the birth mother can change her mind, but it's a lot shorter period than foster-to-adopt.
Foster-to-adopt is the cheapest option, they actually pay you to help cover the costs before the adoption is finalized. The children available range in ages, but most are older than infant, and special needs are common. The biggest problem with this route from my perspective is that it's the most likely to involve you falling in love with a child and not getting to raise them, because you're likely to have them for several months before you know if you'll be able to adopt them. It may be open or closed adoption, depending on why the child is in foster care and what kind of relationship they have with the child. Generally, if they feel that contact isn't likely to harm the child, social services going to push for open adoption.
International adoption is the most expensive - it requires flying to the source country, for one thing. Most of the children will be older than infant, and probably with special needs, including some with needs that you're unlikely to encounter in your home country. These adoptions are pretty much always closed, and once you have the child, you're not going to have to give them back.
