> Professor E McSquared's Calculus Primer: http://www.math.sjsu.edu/~swann/mcsqrd.html -- I actually was poking around my mom's copy when I was about seven or so, but didn't start understanding it until later. The comics made me interested in the content, and I think was a key factor in my growing up enjoying math rather than despising it.

I had a similar experience with "Calculus the Easy Way", and its predecessors "Algebra the Easy Way" and "Trigonometry the Easy Way", all of which I'd highly recommend. They teach the topics as though being invented for the first time by a kingdom finding themselves in need of them.