This book introduce a web page layout weighting scheme for HTML pre-process to deal with degree of importance of information from user s visual perception point of view. By mapping from position, size, and depth of a web page to a degree of freedom, the layout weighting scheme generates a continuous right skew distribution to estimate the importance of a block on a web page of a website, so that we can weight importance of information components in a block for making classification more accuracy. Along with this layout weighting scheme, multi-class support vector machine classifiers are applied to implement classification architecture for websites classification. This book considers that selection of multi-class SVM and kernel functions should be different due to the different application domains, therefore this book proposed a layout weighting scheme and with different kernel functions used by multi-class support vector machine classifiers in experiments in order to find the best performance approach.