To submit a Yahoo Sitemap, first you must go to Yahoo Site Explorer.  At the top of the screen, you will see a sign in link.  Click this link and enter your Yahoo login details.  If you don’t have a Yahoo ID, signup for one by clicking on the sign up text link in the lower right hand part of the sign in window.

Now that you are logged in to Yahoo Site Explorer, enter your full Website URL in the textbox and click on the add my site button.  Your URL will now appear in My Sites.