Google Webmaster blog has one useful article on sitemap FAQ.
Sitemap.xml is the best way to crawl and index your site pages quickly. The pages having no direct links from the main page or those difficult to find to search engine crawlers can be easily discovered by crawler bots from sitemap file.
A sitemap is an xml format file that can be placed on your sites root directory. All your site links are listed in the sitemap.xml file. Sitemap format should be accepted by all search engine bots. The universal standard about sitemap.xml can be found on site sitemap.org.
Summary from Google sitemap FAQs
1) Sitemap.xml file can be used by search engine crawlers to discover the pages from your site.
2) The information in the sitemap.xml file is – All your site URLs and individual page importance. URL importance factor is an index stating the importance of the page for search engines. This is typically a factor from 0 to 1. Crawlers can better understand your site from these links from the sitemap.xml file.
3) Submitting the sitemap to search engine does not mean that your site will get a higher rank. It’s just a way to make search engines aware of your site links.
4) No search engine will penalize your site in terms of ranking or indexing pages for submitting a sitemap file or wrong sitemap file.
5) You can place your sitemap file anywhere on your site domain. Make sure to submit the same path in Webmaster tools. Submit sitemap to Google in Google Webmaster tools here.
6) The preferred sitemap format by search engine bots is XML format over HTML format. However, submitting both formats is a great idea.
7) You can avoid duplicate content penalty from search engines by giving preference to duplicate content URLs, i.e. higher preference for URL that you want to be indexed for the particular content page linked from different URLs.
8 ) Placing the URL at the beginning of your sitemap.xml file does not mean higher preference than URLs placed at the end of sitemap file.
9) You can submit any number of sitemap files for one domain. Make sure to create a sitemap index file in this case.
10) And last great tip: Use this sitemap generator WordPress plugin to create and submit a sitemap to Google.
Submit sitemap to different search engines here:
- Submit sitemap to Google: https://www.google.com/webmasters/tools/
- Submit sitemap to Bing
Don’t waste your time to submit Sitemap to any other search engine!