This book has been designed for exploring new techniques of collection of data and keeping it in the data warehouse & then by following certain techniques & methods to preprocess it and making it free from bad data. These data are available for data mining and these are needed to be made available for proper decision making. In this book, many types of Classification methods of supervised learning has been discussed. These methods are beneficial to give knowledge to the applications. Data warehousing & Data mining is the fast developing field and deals with huge data sets. It is the most acceptable area for Computer science students, researchers, Application developers & Business Tycoons. This dynamic field has taken an important place for shaping the World.