What is the utility of site map submission in the website..?? I dont know the usage of site map in website......
Site map for any website basically improves the user friendly characteristic. You can think a website as a book and then the site map will be the contents of that book. Hence, you can have a through out knowledge of any particular web site and you can go your required page very quickly. Google gives high Page Rank to those sites, having site map.
Well I'm not so sure you will get a high PR just by adding a well-made sitemap but anyway, yes basically it helps Google to figure out how your website is build. You can also customize this to exclude some pages, we do this to have less duplicate content pages. You can easily add a sitemap on any WordPress with Google Sitemap XML plugin. Or just use this http://www.google.com/#hl=en&source=hp&q=free+sitemap+generator Also, don't forget to link to your sitemap from your website, and add your sitemap to your Google Webmaster Tools account. You'll quickly see the benefit when you'll learn how many pages of your website are indexed or not by Google