You may find the following books particularly useful in understanding the Internet:
Bird, Linda. The Complete Guide to Understanding and Using the Internet. Upper Saddle River, NJ: Prentice Hall, 2003.
Comer, Douglas E. The Internet Book. 3rd ed. Englewood Cliffs, NJ: Prentice Hall, 2000.
Gralla, Preston. How the Internet Works. 2nd ed. Indianapolis, Que, 2001.
Underdahl, Brian, and Edward C. Willett. Internet Bible. New York: John Wiley & Sons, 2000.
Young, Margaret Levine. Internet: The Complete Reference. 2nd ed. Berkeley, CA: McGraw-Hill/Osborne, 2002.
To learn more about Usenet and Netnews, consult
Spencer, Henry, and David Lawrence. Managing Usenet. Newton, MA: O’Reilly and Associates, 1998.
There are some books about the Internet Relay Chat that you may want to consult:
Harris, Stuart, The IRC Survival Guide. Reading, MA: Addison-Wesley, 1995.
Powers, James, IRC & Online Chat. Grand Rapids, MI: Abacus, 1997.
Toyer, Kathryn. Learn Advanced Internet Relay Chat. Plano, TX: Wordware, 1998.
The IRC Help web page at http://www.irchelp.org/irchelp/ is a useful web site for resources about the Internet Relay Chat. The newsgroups alt.irc and alt.irc.ircii may also be of interest.