Look for programs that are approved by the National Council for Accreditation of Teacher Education.
For your master's degree, you may be able to choose among master of education, master of science, and master of arts. M.Ed. degree programs probably are more scarce than the other two kinds. They tend to emphasize research less than the other degrees and often do not require a thesis. Your course requirements tend to be more structured. M.A. and M.S. programs are more focused on research, usually require a thesis, and often give you more freedom in your choice of courses. M.A. programs may be slightly more liberal-arts-oriented and less technical than M.S. programs. For example, they may require you to demonstrate competence in a second language.
Check your state's licensing requirements for school administrators. To keep your license current, you may need to take courses throughout your career. This is designed to keep your skills up-to-date.