TITLE: Teichmuller Theory introduction
QUESTION [23 upvotes]: What is a good introduction to Teichmuller theory, mapping class groups etc., and relation to moduli space of curves or Riemann surfaces?

REPLY [2 votes]: McMullen's notes (http://www.math.harvard.edu/~ctm/home/text/class/harvard/275/09/html/base/rs/rs.pdf)