You might research the school district and individual schools for the county, and contact them directly to learn their requirements for becoming one of their teachers (and to learn about positions they have available currently). If the county is located in the United States, you can research the district and schools in SchoolFinder: http://www.education.com/schoolfinder/ (You'll get the best results if you search by city, state and zip code, rather than by county.)
You might also do some research with the department of education for the state. For instance, for California teachers, there is a section on the California Department of Education website that includes professional development resources: http://www.cde.ca.gov/pd/
The state in which you'd like to teach may have something similar.
Here are some additional resources with tips for those seeking to be a teacher: