In order to submit a Sitemap of your website to the Bing Search Engine which was previously known as Live Search by Microsoft.
You need to Login with a Microsoft or hotmail account into the Microsoft/Webmaster Center.
After logging into the Webmaster Center by Bing, you will have to Authenticate the ownership of your website, and you can do that in either placing one XML file authentication into the root folder of your website or adding a meta tag into your webpage.
The Webmaster Center needs this authentication process to ensure that only the rightful owners of a website are making the SiteMap submission to Bing.
Method One of Authentication is fairly easy if you have FTP access to your website, simply download the XML Verification file such as LiveSearchSiteAuth.xml into your Pc, then FTP it into your website and click on Verify website inside Webmaster Center.
From that point onwards you can either submit a single Sitemap of your website via a simple form. Or you can use a simple url such as the one listed here http://www.bing.com/webmaster/ping.aspx?siteMap=http://www.mywebsite.com/mysitemap.xml
Remember that your sitemap need not necessarily be a (.xml) file, it can also be a (.txt) file with a listing of all your website URL each on a separate line. The Text file method seems the easiest and most standard nowadays.