Wikipedia is always good for maths stuff:
http://en.wikipedia.org/wiki/Taylor_series

What you want is the first bit of the definition. In your case, for the Taylor series at x=0, you've got a = 0.  Also, your f(x) = x^2/(1 - x). So f(0) = 0/1 = 0. You need to evaluate the derivatives of x^2/(1 - x) at the point x = 0.

You'll end up with:

f(0) + f'(0) x + (1/2!) f''(0) x + (1/3!) f'''(0) x^2 + ... and so on.

! means factorial btw.