Briefbook of Data Analysis  
   A condensed handbook in encyclopedic format, covering subjects in statistics, computing, analysis and related fields. In HTML: a printed version is available.
   http://physics.web.cern.ch/Physics/DataAnalysis/BriefBook/

Concepts and Applications of Inferential Statistics  
   A full-length and occasionally interactive statistics textbook on the web.
   http://faculty.vassar.edu/~lowry/webtext.html

Current Index to Statistics  
   Requires subscription. Free access to records of 'The American Statistician', and records up to 1994.
   http://query.statindex.org/

InterStat  
   Open source of articles about statistics. Indexed by date, author, title and keyword. PDF,PS.
   http://interstat.stat.vt.edu/INTERSTAT/intro.html-ssi

Medical Statistics at a Glance  
   Companion site for the book by Aviva Petrie and Caroline Sabin (Blackwell). MCQs, self-tests, further resources.
   http://www.medstatsaag.com/

A New View of Statistics  
   An on-line text book of statistics for researchers in biomedical and other empirical sciences.
   http://www.sportsci.org/resource/stats/

Reading Statistics and Research  
   This book helps people become better able to decipher and critique statistically-based research reports.
   http://www.ReadingStats.com/

Reversibility and Stochastic Networks  
   By Frank Kelly, University of Cambridge. Full text of this book now available for download in PDF and DjVu formats.
   http://www.statslab.cam.ac.uk/~frank/rsn.html

Sequential Simplex Optimization  
   Electronic reprint of the classical textbook on improving quality and productivity in research, development, and manufacturing.
   http://www.grabitech.com/

The Statistics Homepage  
   This Electronic Statistical Textbook offers training in the understanding and application of statistics.
   http://www.statsoft.com/textbook/stathome.html

SticiGui  
   Statistics Tools for Internet and Classroom Instruction with a Graphical User Interface, by Philip B. Stark, University of California, Berkeley. An interactive introductory statistics text with dynamic examples and exercises, applets and glossary.
   http://www.stat.berkeley.edu/~stark/SticiGui