Terence Tao

What a legend! As well as being a brilliant mathematicion who won the Fields medal last year, he is also Australian, appears to be a living counter-example to the supposition that all brilliant mathematicians suffer from aspergers syndrome, and most importantly for me, has placed all of the lecture notes from the undergraduate mathematics classes he has taught on the web.

It's the latter that I've really enjoyed reading over in the past week. He has a nice informal style, without losing clarity, and unlike so many others, he somehow manages to present the material at the right level for someone such as me to understand.

Being a genuine prodigy, he also has encouraging words to say to those of us who aren't prodigies (or even very good ;-) ), yet have an interest in mathematics.

If you want an example of what I am talking about, check out this article he wrote about Fourier transforms, in which he starts by explaining how you can decompose any function into "odd" and "even" components, and then generalizes that to arrive at Fourier transforms.