Calculus was originally invented to better describe Isaac Newton's Laws of Motion.  This page is a brief introduction to help with the math required for AP Physics C.

For a historical perspective, you can read The History of Calculus.

WIRED magazine offers up a Crash Course in Calculus for Physics Students.

The Essence of Calculus is a wonderful look at both the how and the why of calculus.  The videos give the viewer a deeper intuition of why you use the rules of calculus.  It's 11 videos long and I highly recommend watching all 11.

Many student find Khan Academy to be a great place to supplement their calculus and physics.  There entire year of calculus can be found below.