Wonderingwhat to do:
Which country are you in?
We recently adopted in Singapore (still waiting for it to be finalised and not crack up under the pressure) and there are advantages/disadvantages.
First stop: British High Comm in the country you're in. Find someone who knows what they're talking about (not easy!). Essentially if you want a UK passport for the baby then the adoption has to be legal in country of birth and then legal in country of residence. Once you legalise in country of residence you can apply for UK passport.
There are a limited number of "birth" countries UK will accept as "legal", and the information is not always obvious from official websites etc. I was told the only blocked countries were Cambodia and Vietnam, but when I looked further Malaysia, Indonesia, Thailand etc were also out (and would have been legalised by Singapore but not accepted by UK).
You then have to find a child, and that's when it gets complicated too, as people in your residence country may not be able to "source" from countries Uk will accept. And UK agencies can't/won't help you as you don't live in the UK.
And then you need to find out the regulations in your country of residence.
When we started looking into this, we kept coming across brick walls, and for a long time didn't think we could find a way round this.
Try and find some kind of adoptive families group where you live, and try and find someone British who's adopted recently.
And tell all your friends there that you're considering adoption and do they know anyone who's done it. In the end the most helpful information we got was from friends of friends.
In the end we found a way through it, and our son came home to us when he was one day old, which was amazing (and with hindsight bloody terrifying!). I was expecting it would take a while to bond, and for the first day it was like someone else's baby that we need to take really good care of. But by day 2, after the nappy changes and the overnight feeds and the little "birdie" crying noises, he was our son. He's almost 4 months and we adore him, and can't remember life without him.
If you happen to live in Singapore, let me know and I'll happily meet you in real life and tell you what I know.
Otherwise, put some feelers out in the expat community.
Good luck!