Hi,

I have created a Fourier Transform tutorial. It is located he

http://www.fourier-series.com/f-transform/index.html

It uses interactive flash programs to help you see how the fourier
transform works. There are currently 5 flash modules with lots of
embedded audio in each module.

The site also includes tutorials on the fourier series, complex
numbers, the discrete fourier transform and some radio frequency
topics.