International moving can be difficult; finding a job in another country, is even more challenging. Work permits are difficult to obtain, and even harder if you're in a two-income household; some countries only allow one spouse to be employed. Despite the rigorous entry requirements and stipulations to acquire a work permit, people are moving internationally to foreign places to seek new opportunities and to experience life somewhere else.
The first step in finding out what you need to work in another country is to contact the consulate or embassy of the country you wish to work in. The U.S. Department of State provides links to embassies located in the U.S. that you can contact for Visa and work permit information.
Project Visa provides information on visitor's visas and work permits for almost every country in the world. A free service, this site is a must for foreign travelers just passing through or people on the move.
Expat Exchange is a great place to learn more about the country you're planning on moving to. With resources listed by country or by subject, you'll find everything you need to make your move a little smoother.
A U.K. based organization, WorkPermit.com provides information on working in 18 countries, most of which are in Europe, the Pacific and North America. It's a great site that provides details and links to other services. There are even international jobs listed and online assessment forms.
Also check out WorkPermit.com's discussion forum where you can ask questions and find answers.
The final resource I'd recommend is a guide to working overseas. Originally just for Canadians, it's been expanded to include Americans who wish to find work internationally. A web version is available free (doesn't include everything from the paper "bible" version, but is still quite extensive) after you fill out a very simple survey. Information also includes advice on relocating overseas, studying and volunteering.