I have heard somewhere that Yahoo like no follow attribute where as google discard them. Please give me valuable advice.
Google and Yahoo SEO is not same both SEO are different from each other.
Yahoo is considered one of the big three along with Google and MSN and by concentrating a little more time and effort on Yahoo optimization it is quite possible to gain a good amount of traffic. With ultra competitive keywords it may actually provide an easier way to generate search traffic than gearing all your efforts solely towards Google.