  This set of four lectures was originally given at the VI Training Course in
the Physics of Correlated Electron systems and High-Tc Superconductors, at
Vietri Sur Mare, Italy (Oct 2001). The lectures are at an introductory level
with exercises. The course describes the physics of moment formation, the Kondo
effect and the development of a coherent heavy electron fluid in the dense
Kondo lattice. The last lecture discusses the open problem of quantum
criticality in heavy electron systems.
