A sitemap is needed to reach the SEO ranking faster . For visitors, sitemap would give a better info about the content of your site since it display all content you have put in your site in one page in the form table of content.
1) Navigation purpose
A sitemap literally acts as a map of your site. If your visitors browses your site and gets lost between the thousands of pages on your site, they can always refer to your sitemap to see where they are, and navigate through your pages with the utmost ease.
2) Conveying your site's theme
By looking at the site map, visitors don't need to waste their time to know your site's content by reading
through each page, and by doing that you will be saving your visitors' time.
3) Site optimization purposes
When you create a sitemap, you are actually creating a single page which contains links to every single page on your site. Imagine what happens when search engine robots hit this page -- they will follow the links on the sitemap and naturally every single page of your site gets indexed by search engines! It is also for this purpose that a link to the sitemap has to be placed prominently on the front page of your website.
4) Organization and relevance
A sitemap enables you to have a complete bird's eye view of your site structure, and whenever you need to add new content or new sections, you will be able to take the existing hierarchy into consideration just by glancing at the sitemap. As a result, you will have a perfectly organized site with everything sorted according to their relevance.
From the above reasons, it is most important to implement a sitemap for website projects with a considerable size. Through this way, you will be able to keep your website easily accesible and neatly organized for everyone. For this purpose you don't need to make your own sitemap for your site. There are so many free plug in to create sitemap in a very simple way for various platform (wordpress :
http://wordpress.org/extend/plugins/google-sitemap-generator/ or blogger :
http://www.mintblogger.com/2009/01/30-blogger-widgets-and-plugins.html, even for static html page etc). For more info,
SITE MAP . If you have problems, feel free to
contact me.