So you aren't an EU citizen but you want to work here.

You would think this might be impossible but its not. There are three ways I know can work.

The first and legal option if you are a Canadian or American citizen is a program through a joint Spanish -North American program. The link for this site is here: http://www.mec.es/sgci/usa/en/programs/us_assistants/default.shtml
The program is simple. You work about 12-16hours a week in a Spanish school, either an elementary or secondary school. You work as an English language assistant and basically are used to expose the children to English. The work isn't that hard, but you do not get to choose your location you select your top 3 choices they inform you and then you decide to go do it. The pay is minimal but enough to support you here, and you can always do private tutoring to supplement your pay. You do not need to have any skills in teaching just apply and find out where you can go.

The second, you may notice the first option was working as an English assistant, is working as an English teacher. Now technically you should have your papers to do this BUT there is so much demand that there are so many English schools and so many companies willing to hire and pay under the table. For this option you will likely need a TEFL or CELTA or some qualification as a teacher for the company to hire you but that is not necessarily the case, at all. The problem of course is pay, as an illegal immigrant (yes, that is what you would be) you have no rights and can't really complain if you don't get paid and all this. I haven't heard of any of these problems but just keep it in mind.

The third is more tricky and involves you needing a very good level of Spanish. I know of a case where you could get hired as a translator this takes some effort and some sleuthing on your part but you could find a way to do it. If you are really curious about this option give me a shout personally.

Those are the three ways I've heard of people surviving here. English teaching is a huge business here, and important for Spanish corporate types trying to move up. Of all the English-speakers I have met here in Madrid, the vast majority teach English. Of course you could move here with your big multinational company, or get a job with a non-profit, or various other options. If you have any crazy ideas contact me, I'll tell you if it will likely work.