After you have your Yahoo! account, and are logged in, you will see this screen.
Select “Submit Site Feed” and enter the URL of your Blog's site feed. You can use either:-
Remember to replace YOURBLOGNAME with that of your Blog's. For Blogger blogs, do not add "www." to YOURBLOGNAME. Once the Sitemaps are submitted, click the “Authentication” link shown at the top right hand corner of the page.
You will now have to authenticate your site ownership with Yahoo!, by either uploading a verification file to your site, or adding a META tag to your site. The authentication via a META tag was only introduced by Yahoo! recently, on Jan 30, 2007.
Note: Blogs created under Blogger.com or Blogspot.com cannot upload a verification file in the root directory. The first method is therefore NOT applicable to you.
The only way to authenticate your Blogger.com and Blogspot.com blogs with Yahoo! is to add a META tag. Copy the META tag that is generated for you, and paste it in your site's home page in the first section of the page, before the first section. What you do is to go to your Blogger dashboard. Under Template ->Edit HTML, somewhere near the top of the script, add the META Tag as follows:-
Remember to replace the META Tag with the code generated by Yahoo! Site Explorer. Once done, Save the Template. When you return to Yahoo! Site Explorer, click the button that says “Ready to Authenticate” as shown below.
You will see a message that says “Your site is pending authentication.” Check back later, and you will notice that your site is now indexed and crawled by Yahoo!
According to the Yahoo Site Explorer instructions:-
“If you have added the META tag, please keep the tag in your site's home page. We will revalidate your site ownership by checking this META tag regularly.”
It is alright to leave this meta tag as well as the Google sitemap meta tag in your template.
You may want to read the articles on how to Submit Blogger sitemap to Google Webmaster and Submit Blogger Sitemap to MSN and Ask.com. Also, submit your Blog to Blog Directories and Feed Directories to let more people know about your Blog. As well, submit your Blog to the various Search Engines for maximum exposure.