Lightspan Professional Development - Lightspan offers courses designed to help teachers help their students. Graduate credit is available from the University of San Diego. It's a resource for degree programs all around the country. Just select your state to learn what degree programs are available in your area. Nova Southeastern University - Nova offers a wide variety of courses geared to educators, including How to Start A Charter School, Theories of Learning, and Creativity in the Curriculum.
Classes start at several intervals during the year.
OnlineLearning.net - This consortium of schools offers classes in several areas of interest, including more than 40 education classes. Fees vary depending on institution. Completion can take as little as 13 months. You can search by college, discipline, or course title. Teach for Tomorrow - Here you'll find an online workshop created just for teachers.