What degrees etc do I need to become a teacher?

I am currently in year 12 and am looking to go to university in September 2012. I want to become a teach however I'm not exactly sure what steps I need to take. I'm looking at teaching primary/secondary students and perhaps specialising in maths, history or humanities in general (history, geography). I know there is a course at Newman's university in Birmingham which is an Initial Teacher Training in primary/secondary Humanities but would I be able to go straight into an ITT course or do I have to do a degree in something first?