Within the EU, it's usually the case that you have to get a work visa before you move over. I know that makes it difficult, but in some ways, I suppose that's the idea.

It depends a bit on what sort of work he does. Most countries set up their immigration policies to discourage unskilled workers or entry level people. It's usually easier if you can transfer within a company or if you have the ability to make one or more exploratory trips (at your own expense) to interview or search for work. Then, once you've gotten a job offer, you have your employer to sponsor your visa application.

If he just comes over as your boyfriend, you're going to have to be the one to sponsor him - which may mean that you will have to promise to support him initially. It would be somewhat easier if you were married.
Cheers,
Bev