There are many great programs both in public higher education and in private colleges and universities. For the most part, acceptance rates in M.Ed. and M.A.T. programs are high, with some schools accepting nearly all applicants. A few of the programs are quite selective, however, particularly if you are applying in highly subscribed areas such as English or Social Studies Education. You may pursue a master's degree if you already have certification or you can obtain both a teaching certificate and a master's degree concurrently. Most programs require that you take the Graduate Record Exam (GRE) but some allow you to substitute the Miller Analogies Test (MAT). GPA requirements range from about 2.5 to 3.0. Many schools look most carefully at the GPA in your major or your GPA in the last two years of undergraduate work. But unlike some other graduate school fields, schools of education rarely have GPA cutoff scores.
Schools that have a competitive admissions process are looking for applicants who have a strong academic record in their discipline, show real enthusiasm and commitment for a career in education, and whose prior experiences in education (tutoring, classroom assisting, coaching etc.) demonstrate that the candidate has given this career choice some thought. Prior coursework in education is not essential but can be helpful, particularly if a field placement was part of the course.
Application deadlines for some of the private universities are in January. Most of the public institutions have rolling admissions or spring deadlines. For private institutions, expect to pay tuition similar to Haverford/Bryn Mawr rates. Financial aid or internships/teaching assistantships are available in some of the programs. Public universities are significantly less expensive, especially for residents.
A good resource in the graduate school search is Peterson's on-line guide to graduate schools (by subject).