The Physics Classroom - An online physics tutorial with good descriptions of most of the physics topics we cover.
HyperPhysics - Another online physics tutorial with good descriptions of most of the physics topics we cover.
PhET - Interactive physics (and other science) simulations and games to help you visualize and interact with the concepts covered in class.
Khan Academy - A vast collection of physics (and many other subjects) video lessons on many of the topics covered. This is a great way to get a feel for a topic that you missed or to get a different explanation than that given by Mr. Riffle.
AP Central - Your (and my) starting place for finding old AP exams for studying and preparing for our unit tests and the AP Exam in May
Flipping Physics - A great set of video reviews and example problems for you to watch.