You have been given good advice above, the most pertinent is to seek advice from a qualified Spanish Tax advisor. I have an accountant do my return beacuse it looks nightmarish, I ensure I am out of Spain for more than 183 days, even though my family is there, to ensure I qualify for the necessary tax break.
I live 100km east if Jerez, in rural Spain this is more a challenge, my 6 year old goes to a Spanish school, she is tri-lingual and is severly criticised because she is more fluent in English as a native speaker than the locals. Dealing with the local institutions such as the Ministry of Interior and the local town hall can be challenging if you dont speak Spanish. On the coast, around Marbella, Malaga, Jerez and Seville there are English schools, however, I cannot comment on the quality.