  These notes grew out of a lecture series given at RIMS in the summer of 2001.
The lecture series was aimed at a broad audience that included many graduate
students. Its purpose lay in familiarizing the audience with the basics of
3-manifold theory and introducing some topics of current research. The first
portion of the lecture series was devoted to standard topics in the theory of
3-manifolds. The middle portion was devoted to a brief study of Heegaaard
splittings and generalized Heegaard splittings. The latter portion touched on a
brand new topic: fork complexes.
