If you have decided to make the move to Spain and are not yet financially self sufficient you might need to seek employment. Like anywhere in Europe at the moment there is a high unemployment rate in Spain and jobs are much harder to come by, especially if you don’t speak Spanish.
Working in Spain as an EU citizen is relatively straight forward. You need your NIE number or Residencia. A fixed contract job (and the best to look for) is known as a Fijo contract (fixed contract). This will provide you with a fixed income where you will be taxed at source.
Many employers do not like to offer these types of contracts as it is much harder to lay someone off without massive financial implications.
Sadly because of this many employers either insist you are autonomo (self-emplyed) or will pay you in ‘black’ money (off the books).
As an autonomo you will be responsible for your own tax affairs and will have to pay monthly Social Security of around 250 euros.