Recognizing that the first day of exams is not when most people will look at the new books shelf (more's the pity), I will highlight just two:
Pictured rocks of the Upper Peninsula is purely a personal choice, as a Michigander and someone who loves the northern parts of the state. Spend just a few minutes with this book and you will feel refreshed and ready for the next exam:
Geology and landscape of Michigan's Pictured Rocks National Lakeshore and vicinity / William L. Blewett.
The world of trees is my second choice. The trees around Oberlin this spring are amazing! - in fact, anything that uses carbon dioxide for growth (anything plant-like, that is) is growing by leaps and bounds. It's a bit alarming, to be honest.