This site includes a short biography of John S. Mill
http://www.cpm.ll.ehime-u.ac.jp/AkamacHomePage/Akamac_E-text_Links/Mill.html
and an extensive listing of various electronic text versions of works by Mill, including over one dozen transcripts of On Liberty, along with a useful source of links relating to Mill.
An essay
http://www.wsu.edu:8080/~wldciv/world_civ_reader/world_civ_reader_2/mill.html
crafted to answer the question What did Mill mean by "the tyranny of the majority"?
An in depth site:
http://www.utilitarianism.com/jsmill.htm
designed as a biography of Mill with built in links to electronic texts of On Liberty and Utilitarianism, two of his greatest works, along with his Autobiography and a glossary of terms used in the study of utilitarianism.
This site
http://www.csulb.edu/~jvancamp/free/Mill_w.html
looks at Mill's overwhelming support of free speech throughout many of his writings, including On Liberty.
A link from the Internet Encyclopedia of Philosophy:
http://www.utm.edu/research/iep/m/milljs.html
it is an exhaustive analysis of Mill's arguments in his works. With summaries and quotations, this site provides an overview of Mill's principles and their connection to each other.
This site
http://www.anova.org/jsmill.html
provides an biography on Mill with less focus on his work and more focus on the man himself. Also, this site places Mill in history with other great philosophers contrasting and comparing Mill's ideas to other philosophers such as Marx. This site is good for a historical perspective and overview of Mill's work.
This link
http://www.blupete.com/Literature/Biographies/Philosophy/Mill.html
has other philosophers' reactions to Mill's work and quotes from Mill on various topics. It is helpful if you need to get an idea on Mill's stance on several issues and how he compares to his latter-day and present-day peers.
