A great place to start are with the Guides to Spain. They provide info on visas, finding work, and the education system. I would also recommend connecting with expats through many expat blogs in Spain. We've completed many expat interviews in Spain that give a great idea what life & the work environment are like.

I would also recommend our new site Expat Quotes - Spain. The writer from "Sunshine and Siestas", Cat Gaa, is completing the country guide with one of the first articles covering "Teaching Jobs in Spain".

Hopefully this helps answer your questions. What other questions do you have? Does anyone have specific advice to offer?