Hi,
You certainly need to start by having a Yahoo account then you can do the following after you log into your Yahoo account:
Go to
http://www.yahoo.comClick on "Suggest a Site" (bottom of page)
Click on "Submit Your Site for Free"
Under "Submit Your Site Feed" enter the url of your xml sitemap and press "Submit Feed"
Yahoo will require you to upload a verification file or use a meta tag in your home page to confirm you are authorized to submit this website's site feed. Once you have completed that step, Yahoo will spider your sitemap.
This should take care of it. If you want to learn more about sitemap generators that will create xml, html, ror, and txt sitemaps on an automated basis for you take a look at this option:
http://www.smartfindsmarketing.com/xml_s…
Hope this helps.