I have been teaching high school Computer Science in Texas for 20 years and have helped other people get their teaching certificate.
You can go through an alternative certification program, but I don’t recommend it. Until you get your certification, you are the first to go when they are cutting positions, and that is happening a lot lately.
I recommend my route, which is to go through a local university, get a defiancy plan and get a traditional teaching certificate. I went that route, and so did several of my friends.
The good thing, is that any courses you take will count towards a Master’s degree, something all school systems like and pay more for.
I needed Speech, Texas Politics and several pedagogy courses. Take them, you’ll find few pedagogy courses that focus on Computer Science and you need the knowledge for the certification test. Student teaching is helpful too.
I was lucky, my district was able to put together a pedagogy course that focused on CS one summer – we used it to develop new curriculum.
I will warn you that teaching CS is probably as hard as working in industry. You don’t have much help, and in fact, most staff development opportunities feel like some type of ego battle. Not sure why, I think it comes from some of the male dominance in the field but the women are as bad if not worse than the men. Actually I think it comes from not being secure in the field – a lot of CS teachers started out as math teachers and feel the need to constantly defend themselves around the true CS people.
The other problem is that everyone in your building expects you fix their stuff. I don’t mind fixing things, but most of the time I have to tell people that their computer is broken and can’t be repaired. They don’t like that.
You often have to teach a lot of different subjects, but I don’t mind it. I found in student teaching, if I had to teach the same course all day, I got bored. Or even just two. So teaching web, CS Fundamentals, PreAP, and AP, plus doing Robotics Extracurricular makes me happy. I know, I’m weird.