If I wanted to complain to my college about the quality of one of my professors this semester, what department would I contact? Or should I contact multiple departments, or even the dean?

This professor has been horrible from the start, but I gave him the benefit of the doubt because it was his first semester at our school and the first time he was teaching ed psych. But last night in class he admited to all of us that he never read the material and only spent maybe 5 minutes looking at the book before each class.