Try a maths for engineers course at your local Uni. If you don't want to or can't enrol, you could probably just sneak in up the back and take notes, I've done this in the past for courses I was just curious about, lecturers usually don't mind. often they enjoy it - someone who actually wants to learn!

There may be something of interest here too, this is the link to Itunes U in ITunes,

http://deimos3.apple.com/indigo/main/main.xml