My teaching certification came through an alternative certification program offered through my regions Alternative Education Service Center after earning my degree in Behavioral Science. The service center provided some of the classes and some were a cooperative endeavor with a local university offering transferable masters level credits as part of the program. The program itself took one year to complete and ended in the required state teacher examinations for content and pedagogy. The major strength of the program for me was two fold. First, I was able to secure a teaching job at full pay and obtain emergency certification while participating in the program. Secondly, the not inconsiderable expense of said program was deducted by my district incrementally from each paycheck for my first year. I found the real life required observations of special needs classrooms to be the most interesting part though the practice tests were in hind sight the most beneficial aspect.
I have to agree with Husky1970. Assuming you know your subject matter and something of classroom management, nothing will give you better training than diving in with a room full of young minds. I have found it also helps to actually ask the students for their ideas on how to improve learning. After you wade through the mandatory sea of “make it more fun” answers, you will find some that actually explain good ways to do just that.