Any teachers out there have information (generally) on certification and student teaching?

I am going to be getting my Masters (in Atmospheric Science) in about a year, and I am thinking I might want to be a high school teacher. Because I didn’t get my undergrad degree in education, or have pursued that path up until now, I am a bit confused as to what will be required of me once I have this second degree. How long does it take to get a certificate? Will I be able to just take the classes required, or will I actually have to become a “real” student again? How long does student teaching tend to last? Any other info would be really helpful. I know certification requirements vary by state, I just thought maybe there were some general ideas.