Shana,
I did alittle web research on your question, and here is what I found...
Foreign adoptions in Spain are exceptionally rare. There are not enough children available for adoption to satisfy the demand of Spanish prospective adoptive parents. Adoptive parents must be legal residents of Spain and must remain in Spain throughout the adoption proceedings.
Prospective parents may not adopt their own descendents or immediate blood relatives, and may not adopt second-degree relatives (i.e. niece, nephew) by blood or marriage.
http://travel.state.gov/family/adopt...untry_324.html
This site also has links to get started.
But from what I read, it really doesn't look easy or very possible.