Lecture #2 was an introduction to AI.
Notes are available in four formats:
Chapter 1 in the textbook covers much the same material as the lecture, so you should read through this if you have the book.
If you want to delve more deeply into the background material on intelligent agents, this is loosely based on Chapter 2 of Artificial Intelligence: A Modern Approach by Stuart Russell and Peter Norvig.
An exellent view of the history of AI can be found in Machines Who Think - A Personal Inquiry into the History and Prospects of Artificial Intelligence by Pamela McCorduck.