Azul,
It's been suggested that I offer some kind of math course here, and maybe I will. First I would need to know if people are interested at all, and what they are interested in.
I am certainly interested (I have, heaven help us!, a master's degree in mathematic), and I can be of help here - but I'm a lousy teacher.
Assuming that we want to look at interesting mathematics (rather than just currently useful mathematics), then the classes of numbers are great fun - counting numbers, integers, rational, real, algebraic, transcendental, complex, etc. And, no, there is not just one sentence to be said about each of them.
Bump
I would do it. I would also note this is a symptom of the dreaded Talossan Disease, where you get hooked and keep inventing new ways to get involved and do things. I hope for an epidemic.