How to obtain Citizen Ship in Spain through marriage.

Does anyone know the process of obtaining residency by being married to a spouse who has a Spanish passport?
I am supposed to marry  a single mother in Spain, as we meet  on Facebook. I have never married before, can anybody tell me the procedure for it.

run, run   and don't look back    ha ha   just kidding   best of luck

Unfortunately the question (thread heading) does not have a simple answer

By Citizenship (I guess you mean Nationality) and Residencia are not the same.  I am British living in Spain.  My wife is Filipino. We marred in her country, she obtained a visitors visa and she came to Spain where, as a non EU citizen she was required to obtain Residencia.   That is done after arriving here through the Foreigners DEpt.

This might be helpful ;   web page

In most cases when one has been resident in Spain for 10 years they can apply through the court for Nationality.  It is not easy to obtain that.