Hi,
It is not a silly question. Balearic Islands Region (Majorca) has the same tax system as spanish mainland but tax rates are different in each region, exceptions are Basque Country and Navarra with their own tax systems.
Canary Islands Region has the same tax system as spanish mainland but it is considered a Special Economic Area with some tax exceptions and reductions, e.g. reduced VAT (cheaper petrol and tobacco,etc).
I recommend you to ask a spanish tax advisor to be sure you make things right because now, due to Spanish Crisis, Hacienda is like an angry watchdog.
Hope you enjoy a beautiful life in Spain.