Replying to Germany University Help

I am currently living just outside of Frankfurt doing my last year of high school, but am loving everything about my new lifestyle and school here. Makes me think, with most colleges be free, or very inexpensive here, why not spend some of my time in college here? So thats where I come to you, if anyone knows, how to start the application process, and what universities are good for the two things I'm going for, international relations and communcations (video editing, production) I will be attending PSU when I return, and dont know too much about college regulations yet, if I could leave PSU for a year, come here and go back, or do I have to go on an "official exchange" between colleges, and thus still pay for credits in the US. Again, any information on what I've asked, any tips, and anything else few and far between to help me try and spend some of my college life, outside of the states.