Hi, we finalized our international adoption a year ago, being EU residents (from 2 different countries here in NL. You first point of contact would be "Stichting Adoptievoorzieningen" (SAV)
http://www.adoptie.nl/. With them, you would also have to register your intent to adopt. If you do not speak Dutch, they do have English language material available. Adoption in the NL is largely international adoption, as there are hardly any domestic adoptions.
Regarding some points the previous poster made: adoption always is a waiting game, in NL as much as in any other country you might reside in. It is true, that there is one bottleneck specific to the Netherlands, which is waiting to be placed in the compulsory pre-adoption course, that is organized centrally by SAV and depending on your province, there might be an additional wait for the home study. Our adoption took 3 years, 2 months.
In principle, you will have to go through the procedure in your country of residence, doing it abroad simply is no option. Unless you move countries. As far as I am aware only US citizens have the options to adopt via the US system as there seem to be structures in place to have your home study done by a certified social worker outside the US.
As for the age regulations, by Dutch adoption law the adopted child may not be more than 40 years younger than the older parent. Unless a few exceptions apply. One can adopt above 40, but a referral needs to be made before the older parent turns 46.
Having adopted an "older" and "special needs" child, I don't quite know what to make of a remark like "(except for much older kids and/or those with severe disabilities/special needs).... " I minimally feel a pang. In the Netherlands a child must be under 6 at referral (unless siblings are involved) and must be able to live independently later on in life. In any case, "older" and "special needs" children are the ones parents are needed for. International adoption is or should at least be considered as finding families for children and not perfect little babies for parents.
In any case, I hope that gets you started, feel free to contact me with more questions.