Data Mining Techniques / Tools
This is a meta site that links to a couple of hundred white papers on IT related topics, including Data Mining.
This textbook contains an introduction to most statistical techniques. For more in depth coverage of the techniques, refer to a good multivariate statistics textbook such as the one by Hair, et al.
For CHAID analysis, go to http://www.tmg-web.com/definitions/chaid.htm.
For CART analysis, go to http://www.tmg-web.com/definitions/cart.htm.
Each gives an overview, interpretation, and pros and cons.