To submit your sitemap to Yahoo you can use the following:
Go to https://siteexplorer.search.yahoo.com/ and complete the following steps.
1. Login to your account.
2. Once logged in you will be redirected to https://siteexplorer.search.yahoo.com/mysites
3. If you haven't previously added your site then enter your website URL in the text field and click on "Add My Site".
4. You will be asked to Authenticate your site ownership using one of two methods.
5. Choose whichever method you prefer then go back to the yahoo page and click on "Ready to Authenticate".
6. Now that your authentication is complete click on "My Sites" then "Feeds".
7. Here you will see the option to add your sitemap (referred to on Yahoo as Feed).
Friday, 13th November 2009