Stephanie at Teaching in Room Six is having an AWESOME linky party! Everyone is linking up with their favorite, go-to resource books. I personally love ordering new teacher resource books from Amazon. I spend all summer reading new books and getting great ideas. My favorite book for teaching middle school:

Teach Like a Champion by Doug Lemov

I has 49 awesome, tested techniques that you can easily put into practice in your classroom. I recommend it to anyone teaching upper elementary school through high school, especially if you teach in an urban or low SES school.