Since no one has really answered your question, let me try even though I just graduated this year. When I was a 1st year, we had PBL 3 times a week. Truthfully, many of my classmates and I thought that PBL was a joke, however, I won't get into the debate that PBL is crap or not. After you get the hang of it i.e. how to b.s. your way through discussion & learning needs, it became really easy. We had dental morphology the 1st two trimesters, which was fairly easy, which was comprised mostly waxing up and carving teeth in wax. The 3rd trimester, which is the summer trimester, was when things got much harder. We had amalgam, occlusion, along with head & neck anatomy. It was a kick in a butt for us since the 1st two semesters were so easy. However, I believe that USC just changed their curriculum and won't make you guys spend so much time in dental morphology anymore. I think they're switching the amalgam course and even have you guys do it the Fall trimester of 1st year. Overall, 1st year will be quite easy relatively to other years. You will have a lot of free time. This is the year if you want to specialize and you want to do research, you will have plenty of time to do so.