I used to read a quarterly magazine called something like "Transitions Abroad," but it was really too general to be useful to me, and likely to you as well, since you're already working in a very specific field. I'd guess that online resources are more plentiful and useful. But there are, obviously, tons of books on this subject; here are the results of an Amazon search:
www.amazon.com/s/ref=nb_ss_gw

If you're looking for casino work, specifically, you may want to begin by checking out the websites of some Spanish casinos; they've got job listing pages. I checked the website for the only casino I've ever been to in Spain, the Casino Barcelona just a minute ago; they're not hiring at the moment. But you probably already know that it's very difficult for non-European citizens to get permission to work legally anywhere in Europe. It might be different for you, as you have a specific skill set that's relatively rare.