StatSoft, an electronic statistics textbook from the makers of the Statistica analysis package.
The Rice University Virtual Lab in Statistics includes David Lane's Hyperstat online textbook, case studies, demonstrations, simulations, and much more.
David Wallace has developed a set of informative animations that explain basic statistical concepts.
Archives of the SPSS mailing list, hosted at the University of Georgia, is completely searchable and probably the first stop for help with SPSS procedures and analyses.
Raynald's SPSS Tools. One of the best sources for SPSS scripts and answers on the web.