Here's a useful website that builds formatted xml sitemaps for you:
http://www.xml-sitemaps.com/
1 Enter your full website URL and some optional parameters in the form below.
2 Press 'Start' button and wait until the site is completely crawled (the progress will be indicated)
2 You will see the generated sitemap details page, including number of pages, broken links list, XML file content and link to a compressed sitemap. Download the sitemap file and place it in the root of your site.
4 Inform Google about your sitemap location using the HTTP request