M. Sipser, Introduction to the Theory of Computation, 2nd Edition, Course Technology, 2006.
J. Hopcroft and J. Ullman, Introduction to Automata Theory. Languages and Computation, Addison-Wesley, 1979 (or the 2nd Edition, 2001, by J. Hopcroft, R. Motwani, and J. Ullman).
You should frequently use the newsgroup for questions and discussions. The staff will monitor the newsgroup and help answer questions. We encourage you to discuss problems with other students here, but please do not post any part of any solutions to a problem (that would be considered as a form of academic misconduct). Postings regarding the definitions and problem formulation are acceptable. The newsgroup can also serve as an opportunity for students to give constructive feedback to the staff in the way the course is being handled. Constructive comments and suggestions that are posted by students could help improve the learning experience for everyone.
To access the newsgroup, go to http://news.cs.illinois.edu.
Information about installing LaTeX can be found here. The installation procedures and available GUI software vary depending on the system that you use.
Here are the files from a LaTeX introduction that Lucas gave in CS173 Fall 2009 with David Morrison (certainly all the typos are Lucas'):
Some useful links: