Advice so far is dead on.

Belize IS a 3rd world country. Job opportunities are very limited and jobs for foreigners generally are in tourist related areas unless you wish to start your own business.

A work permit would be required for the first year (USD$800) and you must have a sponsor. You can get residency after the first year and then you don't need a work permit.

What area of the country are you interested in? If you don't know, then what activities do you wish to persue (this will give us an idea where to start)