Where can I learn about the history of Unix?

The Unix FAQ has a brief section on the history of Unix: http://www.faqs.org/faqs/unix-faq/faq/part6/section-2.html

The Open Group, which controls the UNIX trademark, also has a history and timeline:

For a frequently updated graph of the various Unix implementations and how they relate to one another, see:

At Indiana University, to get support for personal or departmental Linux or Unix systems, see At IU, how do I get support for Linux or Unix?

Also see:

• What does Unix stand for?
• In Unix, where can I get information on differences between the various shells?
• In Unix, what do some obscurely named commands stand for?
• Introduction to Unix commands
• What are SunOS and Solaris?
• What are System V Unix and SVR4?
• In Unix, what are Version 6 and Version 7?
• What is AIX?
• What is BSD?
• What is IRIX?