This book is meant for both beginners and professionals in the filed of data mining. The core concepts of data mining are introduced followed by issues in web mining. Then an algorithm for Web based recommender system is presented with results. This will help readers go from foundation level to application level seamlessly. The presented results can be further improved upon based on this understanding by researchers. Students can benefit by applying these concepts to design their own practical Web mining application. Industry can put these core ideas into practice and benefit as well.