In keeping with the demands for more qualified online teachers, many universities are opting to provide the certification. As with any program, they vary a little from one another by what is offered.
A general overview of each program is provided. Visit the college's website for more information about the specifics of the courses and application process. They are listed in alphabet order, so no precedence is put on one over another. If you know of another not listed here, please let me know. Also, be sure to check the school's site as degrees and certification programs frequently change or become obsolete.
Boise State, Ed Tech (9 credit hours) offers a Graduate Certificate in Online Teaching. This program offers flexibility because it offers courses for K-12 teachers or for teachers of adult learners. Follow the course pathway that best suits the age group you desire to teach. You need a minimum of 3.0 for a grade-point average and need to submit a 500 word personal statement of your goals. You can opt to apply these courses toward a Master's degree.
Boston University Online (16 credit hours) offers a Graduate Certificate in Instructional Technology. Here you will take a course in K-12 online education as well as learning the discipline of e-course delivery and instruction. These too may be transferred toward a Master's degree.
Roosevelt University, Chicago (15 credit hours) offers several graduate certificates related to online teaching. This one is geared toward those who currently teach and want to transfer to an online teaching role. Be sure to check with the college on this specific requirement. A resume is also required.
Thomas Edison State College (12 credit hours), Graduate Certificate in Online Learning and Teaching. Here you take four courses to prepare. You will learn theory and culture, technology, instructional design and communication in an online course. Likewise, these also transfer toward a Master's degree.
University of Illinois Global Campus (16 credit hours) offers a Graduate E-learning Certificate. There are four courses for study which can be obtained in one year. Here you will learn the foundations of teaching online as well as having a choice of three courses to tailor your learning to your specific needs.
All of these choices are from well reputed colleges with accreditation, so do your homework to find the right school and program for you. With this list you certainly have a variety of choices to best suit your educational and professional needs.