Lecture #3 was a fairly non-technical look at some auction theory.
Notes are available in two formats:
The readings for this lecture are the first two chapters of Auctions: Theory and Practice by Paul Klemperer, which the author has made freely available online.
The first chapter is a more detailed look at the material I covered in class, the second explains how to use those techniques to analyse situations that don't at first sight look like auctions.
Section 1.14 gives pointers to surveys of work that has attempted to experimentally verify the theoretical properties of auctions.