This is a common question for webmasters. Here’s a simple compilation of sites geared towards getting your site map into the hands of the search engines. Each search engine generally offers a different set of criteria, and some offer additional XML fields for their sitemaps, but the majority of the popular search engines (google, yahoo, bing, etc..) can read the standard sitemap.xml as long as it’s properly formatted.
Google :
Submit sitemaps through their webmaster tools, at http://www.google.com/webmasters/tools (you will need a webmasters account, which you can sign up for with a google/gmail account)
Bing/Live Search/MSN:
Submit sitemaps through their webmaster center , at http://www.bing.com/webmaster/ (uses either a bing account or you can use your windows live account)
Yahoo!:
Submit site/sitemap to yahoo’s Site Explorer site, at https://siteexplorer.search.yahoo.com/submit
Other search engines will have different submit pages, with links in the footer to their “add” or “submit” pages generally.