I have had similar experiences since making the move 4 years ago. I came across http://www.finance4expats.com by doing a google search and found lots of tax and savings answers there.

OK but remember the accuracy of the information is only as good as the original input and the site owners ability to accurately maintain it.

Tax regimes move very fast (even in Spain) and I see a lot of out of date tax info on many quality sites.

Do your research but dont take any major financial decisions until you are 100% of the facts from qualified persons.