Like Google and Windows Live, Yahoo wants informative, content-rich sites in its index. To improve your chances of ranking well on Yahoo, follow these guidelines:

1. First, review the general guidelines for all search engines
   
   
2. Meta tags
   There’s been much debate about the usefulness (or uselessness) of meta description and keyword tags. Since Google doesn’t index them, many webmasters have abandoned the practice of creating meta tags for their sites.
   
   It’s time to reconsider both the meta description and meta keywords tags! Yahoo indexes and uses both – especially the description tag. To give your site the best chance with all three major spiders, craft a relevant, keyword-rich description and a keywords tag filled with your most important terms. Yahoo encourages webmasters to create a different meta keywords tag for each page of the site rather than using a general set of terms on all pages.
   
   
3. ALT tags
   Accurately describing images on your site using ALT tags can help those who use text browsers view your site. It can also boost your rankings. Yahoo indexes ALT tags and recommends using relevant keywords when creating them.
   
   
4. Unique content
   Like other search engines, Yahoo would like sites in its index to have unique content. If you have many duplicate sites, consider removing them before submitting to Yahoo. This guideline also applies to the two other crawlers – MSNbot and Google.

Yahoo says it best in their guidelines: Create “pages designed primarily for humans, with search engine considerations secondary.” Ultimately, every search engine would prefer if webmasters followed this golden rule.