New to Spain

It is useful to say what nationality you are.  If you are from a country in the EU, you do not need an income to live in Spain.  If not the rest of this does not apply to you. 

You only need to prove your husbands pension to get a targeta sanitaria for health care.  You need to get this from the pensions department of your country.  You need a document from your local town hall to prove you live in the town, even if only renting.  After this you need to go to the police station at the nearest administrative town to get a European citizen card if you have not already got one.  Then go to the local social services office where your house is.  Your husband can apply for the targeta sanitaria and as his spouse you are entitled to the same health care.

While at the social services office your husband can ask where the office is to check if he needs to register for tax in Spain.  We have our pension paid in to an English bank and as we do not work we do not have to pay tax on our income in Spain.

I cant help if you are not EU citizens so perhaps someone else can.

Sorry, I should have said you will need an NIE from the police station before applying for the EU card.  For this you need your pardon (certificate from the town hall). So the order is:

Certificate from pension dept. of country you are from
NIE from police station
padron from town hall
EU citizen card from police station (may also need bank account details)
targeta sanitaria from social services