Physics

I'll be attending Iowa State in two years (I'm going to transfer from Kirkwood) as a physics major. I haven't been able to find much information about educational requirements, so I was wondering if anyone here could help.

Firstly, I was wondering how many years of college are required for a student intending to go into the fields or either nuclear physics or theoretical physics? I know I'll need a doctoral or postdoctoral degree for most jobs in the field; does Iowa State offer either of these, and if not, where is the best institution to acquire them? Is there any other important information I will need to know going into this?

Thanks in advance for any help