There is this very beautiful survey

Nakamura, Hiroaki; Tamagawa, Akio; Mochizuki, Shinichi

The Grothendieck conjecture on the fundamental groups of algebraic curves

http://www.math.okayama-u.ac.jp/~h-naka/zoo/peacock/NTM.ps

You could also have a look at

Szamuely, Tamás

Heidelberg Lectures on Fundamental Groups

http://www.renyi.hu/~szamuely/heid.pdf

There is this very beautiful survey

Nakamura, Hiroaki; Tamagawa, Akio; Mochizuki, Shinichi

The Grothendieck conjecture on the fundamental groups of algebraic curves

http://www.math.sci.osaka-u.ac.jp/~nakamura/zoo/rhino/NTM300.pdf

You could also have a look at

Szamuely, Tamás

Heidelberg Lectures on Fundamental Groups

http://www.renyi.hu/~szamuely/heid.pdf