There is a difference between the regular sitemap that most top websites have and the one they feed to the search engines. Creating an XML sitemap for your website can help the search engines crawl your website more effectively. It won’t get you to the top of the search engines but it is one of those things that you better have on your server. If you know your XML, you can create a sitemap for your website by hand. It will take you a while to do so if you have a complex site structure. You won’t need to write any XML if you use Google XML Sitemaps.
Google XML Sitemaps is a powerful plugin that creates an XML sitemap for your website to help the search engines crawl your content more effectively. It has a ton of option and keeps you in control. This plugin will create a new sitemap when your content changes. It gives you the option to notify the search engines when any update has been made to your site.
If you have a website with thousands of pages, you may not want every single page to be included in your sitemap. This plugin gives you the ability to limit the number of posts you include in your file. You can also choose to exclude categories, archives, and tag pages to reduce the size of your XML file.
Installation notes: It is to note that this plugin won’t work with the multisite version of WordPress 3. The developers are currently working on a version that does work on multi-site WordPress installs. In some cases, you may have to increase your memory to get this plugin to work properly. The execution time may be modified as well.