A big site needs a site map, which should be linked to from every page on the site. Sitemaps offer the opportunity to inform search engines immediately about any changes on your site This will help the search engine robots find every page with just two clicks. A small site needs a site map, too. It's called the navigation bar. There are two techniques to create a sitemap. (1) Download and install a sitemap generator. (2) Use an online sitemap generation tool. The first is more difficult but you have more control over the output. You can download the Google sitemap generator from Google. After you download the package, follow the installation and configuration instructions in it. After you have created the sitemap, you need to upload it to your site and notify Google about its existence. Please Note: Currently Yahoo! and MSN do not support sitemaps. The importance of sitemaps will continue to increase.
I think Yahoo supports the sitemaps. There will be one fine day when all the search engines will accept the sitemaps irrespective of the rivalry.
Sitemap now is universal meaning all SEs supports sitemap (Yahoo, Google, & MSN). It is easy to create one aside from sitemap generator mentioned above you can use sitemapdoc.com.. You can create different format of sitemap like rss, html and the xml...
What if you have over 100.000 unique pages, what do you put in the sitemap? Not all of them I guess :S And using an online tool is a no-go in this situation...
Soical Bookmarking is also affect on PR. Please tell me in detail and thank for your sharing this information.
Thanks for these information guys... But Is it really advisable to use these tools? or is it accurate?
If you are using wordpress, there is a very good site-map generator here designed just for wordpress. http://www.arnebrachhold.de/projects/wordpress-plugins/google-xml-sitemaps-generator/
I'm sorry, but if you need a sitemap for SEO purposes, your site has much bigger problems that you need to deal with. Sitemaps are best used for accessibility and usability, not SEO. Seriously, think about it. What do "SEOs" use sitemaps for? To ensure that their pages get indexed by the search engines. If they really need that help, then they need to take a long, serious and hard look at their site's structure and ensure that the menus are not only text-based but also accessible. Yes, having a sitemap can help, but if I were to have one, I'd rather have it be a plain HTML sitemap (styled with CSS appropriately) and be linked to every page on my site near the menu so that not only those people who prefer to search via a sitemap (rather than a menu or search form) can do so, but also to help ensure that search engine spiders can find it as well.