Italian, just to pick up on what you said about not seeing a picture of the the child before agreeing to adopt them...
What happens is that you start off seeing a photo with a first name and a brief description of the child (this could be through the adoption register, or Be My Parent, or via your agency). If you're keen in principle, you let them know. If they are interested in you, they send you much more detailed information: about 40-60 pages detailing the child's life, health, etc, and also about the birth family, why the child is being put up for adoption etc. We have ALWAYS seen a photo at this point, and with the girl we are adopting we saw photos of birth parents as well.
The child's social workers come to visit you. If they decide they want to proceed with you, you may meet the foster carer at this point. We've met our dd's foster carer twice; she has given us a DVD and photos, which was very appreciated. We also have an appointment to visit the adoption agency's medical advisor, who has done a medical report on our dd.
Our next step, in two weeks, is matching panel. The week after that we finally get to meet our daughter.
It is very strange and frustrating to be so far down the road and still to have not met her. I understand that this is to avoid the 'go down the orphanage and pick up a cute one' thing, and that older children in particular need to be protected from being 'looked over' by potential adopters. But I'm not sure you can altogether know you want to adopt a particular baby until you've held them in your arms...
Anyway, that's the system. Of course, you can in theory pull out at any point up to the adoption being finalised (about six months after child comes to live with you). But of course it becomes harder and harder to do so as you go through the process.
Of course, if you are adopting a small child (ours is 10 months) you have to deal with the fact that you don't quite know what you're getting, in a very real sense, because at that stage many difficulties/issues are still to emerge. With an older child, at least you can go in a lot better informed about what parenting THIS child may be like.
Oh, and don't worry about asking lots of questions. You sound really nice and thoughtful.