To create sitemap go straight to sitemap generator -- it's free, sitemap size is unlimited, it's super :-).
Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL so that search engines can more intelligently crawl the site.
Web crawlers usually discover pages from links within the site and from other sites. Sitemaps supplement this data to allow crawlers that support Sitemaps to pick up all URLs in the Sitemap and learn about those URLs using the associated metadata. Using the Sitemap protocol does not guarantee that web pages are included in search engines, but provides hints for web crawlers to do a better job of crawling your site.
You can find more information in sitemaps and seo chapter
Visit out sitemap builder. It's easy and free and unlimited.
Place it on your server so that it is availble at http://yourSite.de/sitemap.xml
There are some sites on the web that claims, that would submit your sitemap in over 100 pages including Google and Bing, but I wouldn't trust them (f.ex. here). If you can, it's better to do it on your own. To have it done properly: read instruction below.
Make your robots txt look like this
User-agent: * Allow: / Sitemap: http://your-host.com/sitemap.xml
To submit your sitemap in Google you have to sign up for webmaster tools. After sign you have to submit your site in webmaster tools and have to verify it. After that go to site configuration in webmaster tools and click on submit a sitemap.
To submit your site in Bing visit Bing webmaster and sign in to use this tool, to sign in you need a Windows Live ID you can sign up. After login you will be redirected to manage sites. There you can add your site and sitemap by clicking on add a site. On this page you can add your website address and XML sitemap address.