I don't know mathematics, I want to learn it, where to begin?

Practically the most advanced aspect of mathematics that I know is "1 + 1", I want to learn more advanced topics; where to begin?

These two books will get you started, I was very much in the same boat as you and endeavored to improve my mathematical skills in a self directed manner.

"Practical Mathematics", C. I. Palmer (great for practice and learning your stuff in a framework that isn't boring)

"Mathematics for the Nonmathematician", Morris Kline (great for staying inspired, it teaches a lot of history with good exercises)

This website also has some great recommendations for books: http://math-blog.com/2007/07/17/ten-must-read-books-about-ma...

Good luck! I've enjoyed math much more since I've tackled it on my own time and under my own desire.

If you are being literal, than I'd suggest any grade school math book in your library.

Assuming you actually mean that you know algebra/trig (or can review these quickly), I'd suggest a good calculus book. I don't know any off hand, but I'm sure someone here can suggest.

Assuming you know calculus and you want to learn what you have heard of as "real math" there are a few options. 1) You can pick up a good linear algebra book 2) Pick up a book on discrete mathematics 3) Pick up a book on introductory analysis.

I guess a big question is why do you want to do this? For fun? For your job?

mathoverflow would be completely inappropriate for this person; it's aimed at professional mathematicians.