"An imaginary tale, the story of sqrt(-1)" -- it's a great romp through both the history of the imaginary unit and actually gently explains a fair bit of comple

"An imaginary tale, the story of sqrt(-1)" -- it's a great romp through both the history of the imaginary unit and actually gently explains a fair bit of complex analysis to the reader, up to contour integration I think Also, James Gleick's Chaos is a classic, as is the big original beast, Gödel Escher Bach by Douglas Hofstadter.