So I know how to SEO website for google. I already started to show up for the needed keywords on google, but other search engines don't react. I'm having real bad time from yahoo.
Yahoo gave me very little results until very recently. Apparently the traffic from Yahoo is very small compared to Google. Probably Yahoo is more and more loosing users to Google. There is nothing much to do as per SEO for Yahoo. If you do SEO for Google most of the stuffs would be covered for yahoo. Except few cases like meta keywords etc.
I think there is growing complication in the Yahoo and MSN algorithms but this doesnt seem to get much coverage because they dont offer the amount of traffic that Google does. It used to be optimizing for Google would eventually provide results on the other two also; I can say from my own experience this isnt the case anymore.
Yahoo! users give better conversions it seems, though the traffic from Google is much greater. Below is an article about Yahoo! SEO that might help you out. http://www.webpronews.com/expertarticles/2006/10/11/yahoo-seo-techniques
MSN users convert the best all across the board. I noticed with my sites that MSN likes a keyword density of about 3% where as Google and Yahoo like a little more. The biggest factor in my opinion is inbound links. Build links and you will get there.