ya i was thinking to have both format. xml sitemap will be difficult for users and html for G bot. what about msn and yahoo bot?
Have both in your site but submit the sitemap.xml to google through google webmaster tools while the sitemap.html will help understand the human visitors about the overall structure of your site
Be sure to tell spiders where your sitemap is by adding the following to the last line of your robots.txt file. (Be sure to change it for yor website) Sitemap: http://www.YOURWEBSITE.com/sitemap.xml
Sitemap: path-to-your-sitemap-file For EverNewRecipes.com it would be... Sitemap: http://www.evernewrecipes.com/sitemap.xml Code (markup):
Sitemap.html is a standard page within your site to help users to navigate through the most important pages of your site. Large sites use sitemaps to offer more navigation commodity. It's like a book index. Sitemap.xml is a non human interface, auto generated as much as possible, and as often as your site is changing to help Search Engine to crawl through your site in order to index your pages. Your visitors won't see the this xml file. It serves SEO purposes only.
you may want to check this article comparing sitemap types with complete explanations and code examples.
While XML sitemaps are the agreed upon standard for submititng your pages to the major SE's (Google, Yahoo, MSN, and Ask), HTML sitemaps have their place, since they afford the opportunity to use link text in the links to pages and SE's use that text to associate with the destination page. Our CyberSiteSearch product builds sitemaps using different types of link text to product pages to enhance their positioning as more fully discussed here.
All formats will be read by the SEs although the perfer XML.gz (zipped) because they are smaller. It is also advised that you create a web page called site map that has a list of internal urls to the most important pages in your site. The two should not be confused.