Statnotes: an Online Textbook
by G. David Garson, North Carolina State University.
This site contains many topics such as ANOVA, ANCOVA, Cluster Analysis, Correlation, Correspondence Analysis, Logistic Regression, Logit, Probit models, etc. with SPSS related examples. Each topic includes a description of Key Concepts and Terms, Assumptions, FAQ and Bibliography.
Link added: Dec. 23, 2005