Recent drafts of two books are online.

• Complexity Theory: A Modern Approach by Sanjeev Arora and Boaz Barak.
• Computational Complexity: A Conceptual Perspective by Oded Goldreich.

A classic reference which has good coverage of the time and space hierarchy theorems is the book

• Formal languages and their relation to automata by John E. Hopcroft Jeffrey D. Ullman.

Courses at many universities have resulted in excellent scribe notes.

Below I gathered links to some courses on computational complexity theory that produced scribe notes. More will be added.

University	Lecturer	Course
Aarhus University	Peter Bro Miltersen	Computational Complexity Theory, Fall 2006
University of Wisconsin, Madison	Dieter van Melkebeek	CS 810, Complexity Theory, Spring 2007.
University of Wisconsin, Madison	Jin-Yi Cai	CS810: Introduction to Complexity Theory, 2003.
MIT	Madhu Sudan	Advanced Complexity Theory (6.841J/18.405J)
UC Berkeley	Luca Trevisan	CS 278 -- Computational Complexity -- Spring 2008
Tsinghua University	Andrej Bogdanov	80240233: Computational Complexity
Rutgers University	Eric Allender	198:540 -- Combinatorial Methods in Complexity Theory