Think of this as Yahoo’s equivalent to Google’s Webmaster Tools. It’s a much simpler interface and provides a lot less information than what Google has to offer, but it’s still worth it.
To get your blog verified you’ll have to follow a similar procedure to getting it verified with Google Webmaster Tools. Create a page with the title that you get from the Yahoo Site Explorer page and place the other code in the content. After that all you have to do is wait about 24 hours and it will be completed.