Answer:
Traditional Route: Enter into a four-year degree program at a college or university. Some require you to apply specifically for the school of education, in addition to being admitted to the regular university. In this program, you will take teacher education courses as well as student teaching, which is an internship. When you graduate with your bachelor's degree, you will also be qualified to apply for teacher certification in the state in which you went to college. You may have to take a test (PRAXIS or other standardized test) or satisy other certification requirements, depending on which state's certification you are applying for.
Emergency Certification: For adults who already have a bachelor's degree in an area other than teaching, you may be able to be certified under "emergency certification." Depending on your state's needs, you may be able to take courses and internships in a much quicker fashion and without having to earn a separate degree. Often these programs are intended for high-need areas, such as math and science.