abed,
aren’t you the one who posted student with visa d?
anyway, when you get to spain with your student visa, you have to go to the “comisar?a de polic?a” or the oficina de extranjeros.
you will have to fill in the form ex 14 and ex 15 (at least) and print them out.
on page 2 of the forms you will find the documents you need to submit, but of course you may be require more documents by the comisar?a or the oficina de extranjeros.
you can download the forms from
http://www.mir.es/SGACAVT/modelos/extranjeria/modelos_extranje/index.html