Free Programes for computations
http://vassarstats.net/
http://www.victoria.ac.nz/psyc/paul-jose-files/modgraph/modgraph.php
http://www.statisticshell.com/
http://www.afhayes.com/http://homepages.abdn.ac.uk/j.crawford/pages/dept/psychom.htm
http://freestatistics.altervista.org/en/stat.php

Free E-books
http://www.statisticalassociates.com/booklist.htm

SPSS tutorials
http://calcnet.mth.cmich.edu/org/spss/StaProcRegress.htm
http://dontworrymom.com/stats101

Statistical mediation/moderation
http://www.public.asu.edu/~davidpm/ripl/mediate.htm
http://davidakenny.net/cm/mediate.htm
http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html
http://quantpsy.org/interact/mlr2.htm
http://www.jeremydawson.co.uk/slopes.htm

Categorical data
http://www.stat.ufl.edu/~aa/