I submitted a new site to three main search engines: Google, Yahoo and Live.com on 31st March. After 3 days the site URL is included in Google and Live.com but not Yahoo. I was using ordinary submission (no express submission) was really happy my site was included so fast. The only thing is how come it is still not included in Yahoo?
It just takes more time. Wait a week, and then if you still don't get indexed, maybe you have some problems with your site.
submit your site here: http://siteexplorer.search.yahoo.com/ Dont forget to authenticated your site after submit
Yahoo is slow and unpredictable. I've had sites take 3 days to get in to yahoo and others take almost 2 months.