I just finished my first professional book of summer about problem-based inquiry. It was a fantastic read that helped me to better understand the theory behind the method. I left knowing more about how to begin the implementation of it in my classroom. Moving to an International Baccelaurete school where the focus is on units of inquiry into who we are I can see this being one of the best read books of the summer.
In April I was lucky enough to get to go to the NSTA National Conference in San Antonio. I attended several sessions about bringing inquiry into the science classroom. What I liked about Problem-Based Learning is that it is a methodology that can be brought into any subject area. The book discusses how to start your kids off with some teacher directed inquiry and as the year and maturity of kids progresses to more toward student-centered inquiry. If you haven't read it and are wanting to know more about trying out Problem-Based Learning then I would highly recommend this book, great examples and easy to read. He has another great book called Why Are School Buses Always Yellow, again about the inquiry cycle.
Next up for independent study: Science Formative Assessment by Page Keeley
Next up for group book club: Notebook Connections: Strategies for Reader's Notebook by Aimee Bruckner